xref: /vim-8.2.3635/src/eval.c (revision 4490ec4e)
1 /* vi:set ts=8 sts=4 sw=4 noet:
2  *
3  * VIM - Vi IMproved	by Bram Moolenaar
4  *
5  * Do ":help uganda"  in Vim to read copying and usage conditions.
6  * Do ":help credits" in Vim to see a list of people who contributed.
7  * See README.txt for an overview of the Vim source code.
8  */
9 
10 /*
11  * eval.c: Expression evaluation.
12  */
13 #define USING_FLOAT_STUFF
14 
15 #include "vim.h"
16 
17 #if defined(FEAT_EVAL) || defined(PROTO)
18 
19 #ifdef VMS
20 # include <float.h>
21 #endif
22 
23 #define NAMESPACE_CHAR	(char_u *)"abglstvw"
24 
25 /*
26  * When recursively copying lists and dicts we need to remember which ones we
27  * have done to avoid endless recursiveness.  This unique ID is used for that.
28  * The last bit is used for previous_funccal, ignored when comparing.
29  */
30 static int current_copyID = 0;
31 
32 /*
33  * Info used by a ":for" loop.
34  */
35 typedef struct
36 {
37     int		fi_semicolon;	// TRUE if ending in '; var]'
38     int		fi_varcount;	// nr of variables in the list
39     int		fi_break_count;	// nr of line breaks encountered
40     listwatch_T	fi_lw;		// keep an eye on the item used.
41     list_T	*fi_list;	// list being used
42     int		fi_bi;		// index of blob
43     blob_T	*fi_blob;	// blob being used
44     char_u	*fi_string;	// copy of string being used
45     int		fi_byte_idx;	// byte index in fi_string
46 } forinfo_T;
47 
48 static int tv_op(typval_T *tv1, typval_T *tv2, char_u  *op);
49 static int eval2(char_u **arg, typval_T *rettv, evalarg_T *evalarg);
50 static int eval3(char_u **arg, typval_T *rettv, evalarg_T *evalarg);
51 static int eval4(char_u **arg, typval_T *rettv, evalarg_T *evalarg);
52 static int eval5(char_u **arg, typval_T *rettv, evalarg_T *evalarg);
53 static int eval6(char_u **arg, typval_T *rettv, evalarg_T *evalarg, int want_string);
54 static int eval7t(char_u **arg, typval_T *rettv, evalarg_T *evalarg, int want_string);
55 static int eval7(char_u **arg, typval_T *rettv, evalarg_T *evalarg, int want_string);
56 static int eval7_leader(typval_T *rettv, int numeric_only, char_u *start_leader, char_u **end_leaderp);
57 
58 static int free_unref_items(int copyID);
59 static char_u *make_expanded_name(char_u *in_start, char_u *expr_start, char_u *expr_end, char_u *in_end);
60 static char_u *eval_next_line(evalarg_T *evalarg);
61 
62 /*
63  * Return "n1" divided by "n2", taking care of dividing by zero.
64  * If "failed" is not NULL set it to TRUE when dividing by zero fails.
65  */
66 	varnumber_T
67 num_divide(varnumber_T n1, varnumber_T n2, int *failed)
68 {
69     varnumber_T	result;
70 
71     if (n2 == 0)
72     {
73 	if (in_vim9script())
74 	{
75 	    emsg(_(e_divide_by_zero));
76 	    if (failed != NULL)
77 		*failed = TRUE;
78 	}
79 	if (n1 == 0)
80 	    result = VARNUM_MIN; // similar to NaN
81 	else if (n1 < 0)
82 	    result = -VARNUM_MAX;
83 	else
84 	    result = VARNUM_MAX;
85     }
86     else
87 	result = n1 / n2;
88 
89     return result;
90 }
91 
92 /*
93  * Return "n1" modulus "n2", taking care of dividing by zero.
94  * If "failed" is not NULL set it to TRUE when dividing by zero fails.
95  */
96 	varnumber_T
97 num_modulus(varnumber_T n1, varnumber_T n2, int *failed)
98 {
99     if (n2 == 0 && in_vim9script())
100     {
101 	emsg(_(e_divide_by_zero));
102 	if (failed != NULL)
103 	    *failed = TRUE;
104     }
105     return (n2 == 0) ? 0 : (n1 % n2);
106 }
107 
108 /*
109  * Initialize the global and v: variables.
110  */
111     void
112 eval_init(void)
113 {
114     evalvars_init();
115     func_init();
116 
117 #ifdef EBCDIC
118     /*
119      * Sort the function table, to enable binary search.
120      */
121     sortFunctions();
122 #endif
123 }
124 
125 #if defined(EXITFREE) || defined(PROTO)
126     void
127 eval_clear(void)
128 {
129     evalvars_clear();
130     free_scriptnames();  // must come after evalvars_clear().
131     free_locales();
132 
133     // autoloaded script names
134     free_autoload_scriptnames();
135 
136     // unreferenced lists and dicts
137     (void)garbage_collect(FALSE);
138 
139     // functions not garbage collected
140     free_all_functions();
141 }
142 #endif
143 
144     void
145 fill_evalarg_from_eap(evalarg_T *evalarg, exarg_T *eap, int skip)
146 {
147     CLEAR_FIELD(*evalarg);
148     evalarg->eval_flags = skip ? 0 : EVAL_EVALUATE;
149     if (eap != NULL)
150     {
151 	evalarg->eval_cstack = eap->cstack;
152 	if (getline_equal(eap->getline, eap->cookie, getsourceline))
153 	{
154 	    evalarg->eval_getline = eap->getline;
155 	    evalarg->eval_cookie = eap->cookie;
156 	}
157     }
158 }
159 
160 /*
161  * Top level evaluation function, returning a boolean.
162  * Sets "error" to TRUE if there was an error.
163  * Return TRUE or FALSE.
164  */
165     int
166 eval_to_bool(
167     char_u	*arg,
168     int		*error,
169     exarg_T	*eap,
170     int		skip)	    // only parse, don't execute
171 {
172     typval_T	tv;
173     varnumber_T	retval = FALSE;
174     evalarg_T	evalarg;
175 
176     fill_evalarg_from_eap(&evalarg, eap, skip);
177 
178     if (skip)
179 	++emsg_skip;
180     if (eval0(arg, &tv, eap, &evalarg) == FAIL)
181 	*error = TRUE;
182     else
183     {
184 	*error = FALSE;
185 	if (!skip)
186 	{
187 	    if (in_vim9script())
188 		retval = tv_get_bool_chk(&tv, error);
189 	    else
190 		retval = (tv_get_number_chk(&tv, error) != 0);
191 	    clear_tv(&tv);
192 	}
193     }
194     if (skip)
195 	--emsg_skip;
196     clear_evalarg(&evalarg, eap);
197 
198     return (int)retval;
199 }
200 
201 /*
202  * Call eval1() and give an error message if not done at a lower level.
203  */
204     static int
205 eval1_emsg(char_u **arg, typval_T *rettv, exarg_T *eap)
206 {
207     char_u	*start = *arg;
208     int		ret;
209     int		did_emsg_before = did_emsg;
210     int		called_emsg_before = called_emsg;
211     evalarg_T	evalarg;
212 
213     fill_evalarg_from_eap(&evalarg, eap, eap != NULL && eap->skip);
214 
215     ret = eval1(arg, rettv, &evalarg);
216     if (ret == FAIL)
217     {
218 	// Report the invalid expression unless the expression evaluation has
219 	// been cancelled due to an aborting error, an interrupt, or an
220 	// exception, or we already gave a more specific error.
221 	// Also check called_emsg for when using assert_fails().
222 	if (!aborting() && did_emsg == did_emsg_before
223 					  && called_emsg == called_emsg_before)
224 	    semsg(_(e_invalid_expression_str), start);
225     }
226     clear_evalarg(&evalarg, eap);
227     return ret;
228 }
229 
230 /*
231  * Return whether a typval is a valid expression to pass to eval_expr_typval()
232  * or eval_expr_to_bool().  An empty string returns FALSE;
233  */
234     int
235 eval_expr_valid_arg(typval_T *tv)
236 {
237     return tv->v_type != VAR_UNKNOWN
238 	    && (tv->v_type != VAR_STRING
239 		  || (tv->vval.v_string != NULL && *tv->vval.v_string != NUL));
240 }
241 
242 /*
243  * Evaluate an expression, which can be a function, partial or string.
244  * Pass arguments "argv[argc]".
245  * Return the result in "rettv" and OK or FAIL.
246  */
247     int
248 eval_expr_typval(typval_T *expr, typval_T *argv, int argc, typval_T *rettv)
249 {
250     char_u	*s;
251     char_u	buf[NUMBUFLEN];
252     funcexe_T	funcexe;
253 
254     if (expr->v_type == VAR_FUNC)
255     {
256 	s = expr->vval.v_string;
257 	if (s == NULL || *s == NUL)
258 	    return FAIL;
259 	CLEAR_FIELD(funcexe);
260 	funcexe.evaluate = TRUE;
261 	if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
262 	    return FAIL;
263     }
264     else if (expr->v_type == VAR_PARTIAL)
265     {
266 	partial_T   *partial = expr->vval.v_partial;
267 
268 	if (partial == NULL)
269 	    return FAIL;
270 
271 	if (partial->pt_func != NULL
272 			  && partial->pt_func->uf_def_status != UF_NOT_COMPILED)
273 	{
274 	    if (call_def_function(partial->pt_func, argc, argv,
275 						       partial, rettv) == FAIL)
276 		return FAIL;
277 	}
278 	else
279 	{
280 	    s = partial_name(partial);
281 	    if (s == NULL || *s == NUL)
282 		return FAIL;
283 	    CLEAR_FIELD(funcexe);
284 	    funcexe.evaluate = TRUE;
285 	    funcexe.partial = partial;
286 	    if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL)
287 		return FAIL;
288 	}
289     }
290     else if (expr->v_type == VAR_INSTR)
291     {
292 	return exe_typval_instr(expr, rettv);
293     }
294     else
295     {
296 	s = tv_get_string_buf_chk(expr, buf);
297 	if (s == NULL)
298 	    return FAIL;
299 	s = skipwhite(s);
300 	if (eval1_emsg(&s, rettv, NULL) == FAIL)
301 	    return FAIL;
302 	if (*skipwhite(s) != NUL)  // check for trailing chars after expr
303 	{
304 	    clear_tv(rettv);
305 	    semsg(_(e_invalid_expression_str), s);
306 	    return FAIL;
307 	}
308     }
309     return OK;
310 }
311 
312 /*
313  * Like eval_to_bool() but using a typval_T instead of a string.
314  * Works for string, funcref and partial.
315  */
316     int
317 eval_expr_to_bool(typval_T *expr, int *error)
318 {
319     typval_T	rettv;
320     int		res;
321 
322     if (eval_expr_typval(expr, NULL, 0, &rettv) == FAIL)
323     {
324 	*error = TRUE;
325 	return FALSE;
326     }
327     res = (tv_get_bool_chk(&rettv, error) != 0);
328     clear_tv(&rettv);
329     return res;
330 }
331 
332 /*
333  * Top level evaluation function, returning a string.  If "skip" is TRUE,
334  * only parsing to "nextcmd" is done, without reporting errors.  Return
335  * pointer to allocated memory, or NULL for failure or when "skip" is TRUE.
336  */
337     char_u *
338 eval_to_string_skip(
339     char_u	*arg,
340     exarg_T	*eap,
341     int		skip)	    // only parse, don't execute
342 {
343     typval_T	tv;
344     char_u	*retval;
345     evalarg_T	evalarg;
346 
347     fill_evalarg_from_eap(&evalarg, eap, skip);
348     if (skip)
349 	++emsg_skip;
350     if (eval0(arg, &tv, eap, &evalarg) == FAIL || skip)
351 	retval = NULL;
352     else
353     {
354 	retval = vim_strsave(tv_get_string(&tv));
355 	clear_tv(&tv);
356     }
357     if (skip)
358 	--emsg_skip;
359     clear_evalarg(&evalarg, eap);
360 
361     return retval;
362 }
363 
364 /*
365  * Skip over an expression at "*pp".
366  * Return FAIL for an error, OK otherwise.
367  */
368     int
369 skip_expr(char_u **pp, evalarg_T *evalarg)
370 {
371     typval_T	rettv;
372 
373     *pp = skipwhite(*pp);
374     return eval1(pp, &rettv, evalarg);
375 }
376 
377 /*
378  * Skip over an expression at "*arg".
379  * If in Vim9 script and line breaks are encountered, the lines are
380  * concatenated.  "evalarg->eval_tofree" will be set accordingly.
381  * "arg" is advanced to just after the expression.
382  * "start" is set to the start of the expression, "end" to just after the end.
383  * Also when the expression is copied to allocated memory.
384  * Return FAIL for an error, OK otherwise.
385  */
386     int
387 skip_expr_concatenate(
388 	char_u	    **arg,
389 	char_u	    **start,
390 	char_u	    **end,
391 	evalarg_T   *evalarg)
392 {
393     typval_T	rettv;
394     int		res;
395     int		vim9script = in_vim9script();
396     garray_T    *gap = evalarg == NULL ? NULL : &evalarg->eval_ga;
397     garray_T    *freegap = evalarg == NULL ? NULL : &evalarg->eval_freega;
398     int		save_flags = evalarg == NULL ? 0 : evalarg->eval_flags;
399     int		evaluate = evalarg == NULL
400 			       ? FALSE : (evalarg->eval_flags & EVAL_EVALUATE);
401 
402     if (vim9script && evaluate
403 	       && (evalarg->eval_cookie != NULL || evalarg->eval_cctx != NULL))
404     {
405 	ga_init2(gap, sizeof(char_u *), 10);
406 	// leave room for "start"
407 	if (ga_grow(gap, 1) == OK)
408 	    ++gap->ga_len;
409 	ga_init2(freegap, sizeof(char_u *), 10);
410     }
411     *start = *arg;
412 
413     // Don't evaluate the expression.
414     if (evalarg != NULL)
415 	evalarg->eval_flags &= ~EVAL_EVALUATE;
416     *arg = skipwhite(*arg);
417     res = eval1(arg, &rettv, evalarg);
418     *end = *arg;
419     if (evalarg != NULL)
420 	evalarg->eval_flags = save_flags;
421 
422     if (vim9script && evaluate
423 	    && (evalarg->eval_cookie != NULL || evalarg->eval_cctx != NULL))
424     {
425 	if (evalarg->eval_ga.ga_len == 1)
426 	{
427 	    // just the one line, no need to concatenate
428 	    ga_clear(gap);
429 	    gap->ga_itemsize = 0;
430 	}
431 	else
432 	{
433 	    char_u	    *p;
434 	    size_t	    endoff = STRLEN(*arg);
435 
436 	    // Line breaks encountered, concatenate all the lines.
437 	    *((char_u **)gap->ga_data) = *start;
438 	    p = ga_concat_strings(gap, " ");
439 
440 	    // free the lines only when using getsourceline()
441 	    if (evalarg->eval_cookie != NULL)
442 	    {
443 		// Do not free the first line, the caller can still use it.
444 		*((char_u **)gap->ga_data) = NULL;
445 		// Do not free the last line, "arg" points into it, free it
446 		// later.
447 		vim_free(evalarg->eval_tofree);
448 		evalarg->eval_tofree =
449 				    ((char_u **)gap->ga_data)[gap->ga_len - 1];
450 		((char_u **)gap->ga_data)[gap->ga_len - 1] = NULL;
451 		ga_clear_strings(gap);
452 	    }
453 	    else
454 	    {
455 		ga_clear(gap);
456 
457 		// free lines that were explicitly marked for freeing
458 		ga_clear_strings(freegap);
459 	    }
460 
461 	    gap->ga_itemsize = 0;
462 	    if (p == NULL)
463 		return FAIL;
464 	    *start = p;
465 	    vim_free(evalarg->eval_tofree_lambda);
466 	    evalarg->eval_tofree_lambda = p;
467 	    // Compute "end" relative to the end.
468 	    *end = *start + STRLEN(*start) - endoff;
469 	}
470     }
471 
472     return res;
473 }
474 
475 /*
476  * Convert "tv" to a string.
477  * When "convert" is TRUE convert a List into a sequence of lines and convert
478  * a Float to a String.
479  * Returns an allocated string (NULL when out of memory).
480  */
481     char_u *
482 typval2string(typval_T *tv, int convert)
483 {
484     garray_T	ga;
485     char_u	*retval;
486 #ifdef FEAT_FLOAT
487     char_u	numbuf[NUMBUFLEN];
488 #endif
489 
490     if (convert && tv->v_type == VAR_LIST)
491     {
492 	ga_init2(&ga, (int)sizeof(char), 80);
493 	if (tv->vval.v_list != NULL)
494 	{
495 	    list_join(&ga, tv->vval.v_list, (char_u *)"\n", TRUE, FALSE, 0);
496 	    if (tv->vval.v_list->lv_len > 0)
497 		ga_append(&ga, NL);
498 	}
499 	ga_append(&ga, NUL);
500 	retval = (char_u *)ga.ga_data;
501     }
502 #ifdef FEAT_FLOAT
503     else if (convert && tv->v_type == VAR_FLOAT)
504     {
505 	vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
506 	retval = vim_strsave(numbuf);
507     }
508 #endif
509     else
510 	retval = vim_strsave(tv_get_string(tv));
511     return retval;
512 }
513 
514 /*
515  * Top level evaluation function, returning a string.  Does not handle line
516  * breaks.
517  * When "convert" is TRUE convert a List into a sequence of lines and convert
518  * a Float to a String.
519  * Return pointer to allocated memory, or NULL for failure.
520  */
521     char_u *
522 eval_to_string_eap(
523     char_u	*arg,
524     int		convert,
525     exarg_T	*eap)
526 {
527     typval_T	tv;
528     char_u	*retval;
529     evalarg_T	evalarg;
530 
531     fill_evalarg_from_eap(&evalarg, eap, eap != NULL && eap->skip);
532     if (eval0(arg, &tv, NULL, &evalarg) == FAIL)
533 	retval = NULL;
534     else
535     {
536 	retval = typval2string(&tv, convert);
537 	clear_tv(&tv);
538     }
539     clear_evalarg(&evalarg, NULL);
540 
541     return retval;
542 }
543 
544     char_u *
545 eval_to_string(
546     char_u	*arg,
547     int		convert)
548 {
549     return eval_to_string_eap(arg, convert, NULL);
550 }
551 
552 /*
553  * Call eval_to_string() without using current local variables and using
554  * textwinlock.  When "use_sandbox" is TRUE use the sandbox.
555  * Use legacy Vim script syntax.
556  */
557     char_u *
558 eval_to_string_safe(
559     char_u	*arg,
560     int		use_sandbox)
561 {
562     char_u	*retval;
563     funccal_entry_T funccal_entry;
564     int		save_sc_version = current_sctx.sc_version;
565 
566     current_sctx.sc_version = 1;
567     save_funccal(&funccal_entry);
568     if (use_sandbox)
569 	++sandbox;
570     ++textwinlock;
571     retval = eval_to_string(arg, FALSE);
572     if (use_sandbox)
573 	--sandbox;
574     --textwinlock;
575     restore_funccal();
576     current_sctx.sc_version = save_sc_version;
577     return retval;
578 }
579 
580 /*
581  * Top level evaluation function, returning a number.
582  * Evaluates "expr" silently.
583  * Returns -1 for an error.
584  */
585     varnumber_T
586 eval_to_number(char_u *expr)
587 {
588     typval_T	rettv;
589     varnumber_T	retval;
590     char_u	*p = skipwhite(expr);
591 
592     ++emsg_off;
593 
594     if (eval1(&p, &rettv, &EVALARG_EVALUATE) == FAIL)
595 	retval = -1;
596     else
597     {
598 	retval = tv_get_number_chk(&rettv, NULL);
599 	clear_tv(&rettv);
600     }
601     --emsg_off;
602 
603     return retval;
604 }
605 
606 /*
607  * Top level evaluation function.
608  * Returns an allocated typval_T with the result.
609  * Returns NULL when there is an error.
610  */
611     typval_T *
612 eval_expr(char_u *arg, exarg_T *eap)
613 {
614     typval_T	*tv;
615     evalarg_T	evalarg;
616 
617     fill_evalarg_from_eap(&evalarg, eap, eap != NULL && eap->skip);
618 
619     tv = ALLOC_ONE(typval_T);
620     if (tv != NULL && eval0(arg, tv, eap, &evalarg) == FAIL)
621 	VIM_CLEAR(tv);
622 
623     clear_evalarg(&evalarg, eap);
624     return tv;
625 }
626 
627 /*
628  * Call some Vim script function and return the result in "*rettv".
629  * Uses argv[0] to argv[argc - 1] for the function arguments.  argv[argc]
630  * should have type VAR_UNKNOWN.
631  * Returns OK or FAIL.
632  */
633     int
634 call_vim_function(
635     char_u      *func,
636     int		argc,
637     typval_T	*argv,
638     typval_T	*rettv)
639 {
640     int		ret;
641     funcexe_T	funcexe;
642 
643     rettv->v_type = VAR_UNKNOWN;		// clear_tv() uses this
644     CLEAR_FIELD(funcexe);
645     funcexe.firstline = curwin->w_cursor.lnum;
646     funcexe.lastline = curwin->w_cursor.lnum;
647     funcexe.evaluate = TRUE;
648     ret = call_func(func, -1, rettv, argc, argv, &funcexe);
649     if (ret == FAIL)
650 	clear_tv(rettv);
651 
652     return ret;
653 }
654 
655 /*
656  * Call Vim script function "func" and return the result as a number.
657  * Returns -1 when calling the function fails.
658  * Uses argv[0] to argv[argc - 1] for the function arguments. argv[argc] should
659  * have type VAR_UNKNOWN.
660  */
661     varnumber_T
662 call_func_retnr(
663     char_u      *func,
664     int		argc,
665     typval_T	*argv)
666 {
667     typval_T	rettv;
668     varnumber_T	retval;
669 
670     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
671 	return -1;
672 
673     retval = tv_get_number_chk(&rettv, NULL);
674     clear_tv(&rettv);
675     return retval;
676 }
677 
678 /*
679  * Call Vim script function like call_func_retnr() and drop the result.
680  * Returns FAIL when calling the function fails.
681  */
682     int
683 call_func_noret(
684     char_u      *func,
685     int		argc,
686     typval_T	*argv)
687 {
688     typval_T	rettv;
689 
690     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
691 	return FAIL;
692     clear_tv(&rettv);
693     return OK;
694 }
695 
696 /*
697  * Call Vim script function "func" and return the result as a string.
698  * Uses "argv" and "argc" as call_func_retnr().
699  * Returns NULL when calling the function fails.
700  */
701     void *
702 call_func_retstr(
703     char_u      *func,
704     int		argc,
705     typval_T	*argv)
706 {
707     typval_T	rettv;
708     char_u	*retval;
709 
710     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
711 	return NULL;
712 
713     retval = vim_strsave(tv_get_string(&rettv));
714     clear_tv(&rettv);
715     return retval;
716 }
717 
718 /*
719  * Call Vim script function "func" and return the result as a List.
720  * Uses "argv" and "argc" as call_func_retnr().
721  * Returns NULL when there is something wrong.
722  */
723     void *
724 call_func_retlist(
725     char_u      *func,
726     int		argc,
727     typval_T	*argv)
728 {
729     typval_T	rettv;
730 
731     if (call_vim_function(func, argc, argv, &rettv) == FAIL)
732 	return NULL;
733 
734     if (rettv.v_type != VAR_LIST)
735     {
736 	clear_tv(&rettv);
737 	return NULL;
738     }
739 
740     return rettv.vval.v_list;
741 }
742 
743 #ifdef FEAT_FOLDING
744 /*
745  * Evaluate "arg", which is 'foldexpr'.
746  * Note: caller must set "curwin" to match "arg".
747  * Returns the foldlevel, and any character preceding it in "*cp".  Doesn't
748  * give error messages.
749  */
750     int
751 eval_foldexpr(char_u *arg, int *cp)
752 {
753     typval_T	tv;
754     varnumber_T	retval;
755     char_u	*s;
756     int		use_sandbox = was_set_insecurely((char_u *)"foldexpr",
757 								   OPT_LOCAL);
758 
759     ++emsg_off;
760     if (use_sandbox)
761 	++sandbox;
762     ++textwinlock;
763     *cp = NUL;
764     if (eval0(arg, &tv, NULL, &EVALARG_EVALUATE) == FAIL)
765 	retval = 0;
766     else
767     {
768 	// If the result is a number, just return the number.
769 	if (tv.v_type == VAR_NUMBER)
770 	    retval = tv.vval.v_number;
771 	else if (tv.v_type != VAR_STRING || tv.vval.v_string == NULL)
772 	    retval = 0;
773 	else
774 	{
775 	    // If the result is a string, check if there is a non-digit before
776 	    // the number.
777 	    s = tv.vval.v_string;
778 	    if (!VIM_ISDIGIT(*s) && *s != '-')
779 		*cp = *s++;
780 	    retval = atol((char *)s);
781 	}
782 	clear_tv(&tv);
783     }
784     --emsg_off;
785     if (use_sandbox)
786 	--sandbox;
787     --textwinlock;
788     clear_evalarg(&EVALARG_EVALUATE, NULL);
789 
790     return (int)retval;
791 }
792 #endif
793 
794 /*
795  * Get an lval: variable, Dict item or List item that can be assigned a value
796  * to: "name", "na{me}", "name[expr]", "name[expr:expr]", "name[expr][expr]",
797  * "name.key", "name.key[expr]" etc.
798  * Indexing only works if "name" is an existing List or Dictionary.
799  * "name" points to the start of the name.
800  * If "rettv" is not NULL it points to the value to be assigned.
801  * "unlet" is TRUE for ":unlet": slightly different behavior when something is
802  * wrong; must end in space or cmd separator.
803  *
804  * flags:
805  *  GLV_QUIET:       do not give error messages
806  *  GLV_READ_ONLY:   will not change the variable
807  *  GLV_NO_AUTOLOAD: do not use script autoloading
808  *
809  * Returns a pointer to just after the name, including indexes.
810  * When an evaluation error occurs "lp->ll_name" is NULL;
811  * Returns NULL for a parsing error.  Still need to free items in "lp"!
812  */
813     char_u *
814 get_lval(
815     char_u	*name,
816     typval_T	*rettv,
817     lval_T	*lp,
818     int		unlet,
819     int		skip,
820     int		flags,	    // GLV_ values
821     int		fne_flags)  // flags for find_name_end()
822 {
823     char_u	*p;
824     char_u	*expr_start, *expr_end;
825     int		cc;
826     dictitem_T	*v;
827     typval_T	var1;
828     typval_T	var2;
829     int		empty1 = FALSE;
830     listitem_T	*ni;
831     char_u	*key = NULL;
832     int		len;
833     hashtab_T	*ht = NULL;
834     int		quiet = flags & GLV_QUIET;
835     int		writing;
836 
837     // Clear everything in "lp".
838     CLEAR_POINTER(lp);
839 
840     if (skip || (flags & GLV_COMPILING))
841     {
842 	// When skipping or compiling just find the end of the name.
843 	lp->ll_name = name;
844 	lp->ll_name_end = find_name_end(name, NULL, NULL,
845 						      FNE_INCL_BR | fne_flags);
846 	return lp->ll_name_end;
847     }
848 
849     // Find the end of the name.
850     p = find_name_end(name, &expr_start, &expr_end, fne_flags);
851     lp->ll_name_end = p;
852     if (expr_start != NULL)
853     {
854 	// Don't expand the name when we already know there is an error.
855 	if (unlet && !VIM_ISWHITE(*p) && !ends_excmd(*p)
856 						    && *p != '[' && *p != '.')
857 	{
858 	    semsg(_(e_trailing_arg), p);
859 	    return NULL;
860 	}
861 
862 	lp->ll_exp_name = make_expanded_name(name, expr_start, expr_end, p);
863 	if (lp->ll_exp_name == NULL)
864 	{
865 	    // Report an invalid expression in braces, unless the
866 	    // expression evaluation has been cancelled due to an
867 	    // aborting error, an interrupt, or an exception.
868 	    if (!aborting() && !quiet)
869 	    {
870 		emsg_severe = TRUE;
871 		semsg(_(e_invarg2), name);
872 		return NULL;
873 	    }
874 	}
875 	lp->ll_name = lp->ll_exp_name;
876     }
877     else
878     {
879 	lp->ll_name = name;
880 
881 	if (in_vim9script())
882 	{
883 	    // "a: type" is declaring variable "a" with a type, not "a:".
884 	    if (p == name + 2 && p[-1] == ':')
885 	    {
886 		--p;
887 		lp->ll_name_end = p;
888 	    }
889 	    if (*p == ':')
890 	    {
891 		scriptitem_T *si = SCRIPT_ITEM(current_sctx.sc_sid);
892 		char_u	 *tp = skipwhite(p + 1);
893 
894 		// parse the type after the name
895 		lp->ll_type = parse_type(&tp, &si->sn_type_list, !quiet);
896 		if (lp->ll_type == NULL && !quiet)
897 		    return NULL;
898 		lp->ll_name_end = tp;
899 	    }
900 	}
901     }
902 
903     // Without [idx] or .key we are done.
904     if ((*p != '[' && *p != '.') || lp->ll_name == NULL)
905 	return p;
906 
907     cc = *p;
908     *p = NUL;
909     // When we would write to the variable pass &ht and prevent autoload.
910     writing = !(flags & GLV_READ_ONLY);
911     v = find_var(lp->ll_name, writing ? &ht : NULL,
912 					 (flags & GLV_NO_AUTOLOAD) || writing);
913     if (v == NULL && !quiet)
914 	semsg(_(e_undefined_variable_str), lp->ll_name);
915     *p = cc;
916     if (v == NULL)
917 	return NULL;
918 
919     if (in_vim9script() && (flags & GLV_NO_DECL) == 0)
920     {
921 	if (!quiet)
922 	    semsg(_(e_variable_already_declared), lp->ll_name);
923 	return NULL;
924     }
925 
926     /*
927      * Loop until no more [idx] or .key is following.
928      */
929     lp->ll_tv = &v->di_tv;
930     var1.v_type = VAR_UNKNOWN;
931     var2.v_type = VAR_UNKNOWN;
932     while (*p == '[' || (*p == '.' && p[1] != '=' && p[1] != '.'))
933     {
934 	if (*p == '.' && lp->ll_tv->v_type != VAR_DICT)
935 	{
936 	    if (!quiet)
937 		semsg(_(e_dot_can_only_be_used_on_dictionary_str), name);
938 	    return NULL;
939 	}
940 	if (lp->ll_tv->v_type != VAR_LIST
941 		&& lp->ll_tv->v_type != VAR_DICT
942 		&& lp->ll_tv->v_type != VAR_BLOB)
943 	{
944 	    if (!quiet)
945 		emsg(_("E689: Can only index a List, Dictionary or Blob"));
946 	    return NULL;
947 	}
948 
949 	// a NULL list/blob works like an empty list/blob, allocate one now.
950 	if (lp->ll_tv->v_type == VAR_LIST && lp->ll_tv->vval.v_list == NULL)
951 	    rettv_list_alloc(lp->ll_tv);
952 	else if (lp->ll_tv->v_type == VAR_BLOB
953 					     && lp->ll_tv->vval.v_blob == NULL)
954 	    rettv_blob_alloc(lp->ll_tv);
955 
956 	if (lp->ll_range)
957 	{
958 	    if (!quiet)
959 		emsg(_("E708: [:] must come last"));
960 	    return NULL;
961 	}
962 
963 	if (in_vim9script() && lp->ll_valtype == NULL
964 		&& lp->ll_tv == &v->di_tv
965 		&& ht != NULL && ht == get_script_local_ht())
966 	{
967 	    svar_T  *sv = find_typval_in_script(lp->ll_tv);
968 
969 	    // Vim9 script local variable: get the type
970 	    if (sv != NULL)
971 		lp->ll_valtype = sv->sv_type;
972 	}
973 
974 	len = -1;
975 	if (*p == '.')
976 	{
977 	    key = p + 1;
978 	    for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
979 		;
980 	    if (len == 0)
981 	    {
982 		if (!quiet)
983 		    emsg(_(e_emptykey));
984 		return NULL;
985 	    }
986 	    p = key + len;
987 	}
988 	else
989 	{
990 	    // Get the index [expr] or the first index [expr: ].
991 	    p = skipwhite(p + 1);
992 	    if (*p == ':')
993 		empty1 = TRUE;
994 	    else
995 	    {
996 		empty1 = FALSE;
997 		if (eval1(&p, &var1, &EVALARG_EVALUATE) == FAIL)  // recursive!
998 		    return NULL;
999 		if (tv_get_string_chk(&var1) == NULL)
1000 		{
1001 		    // not a number or string
1002 		    clear_tv(&var1);
1003 		    return NULL;
1004 		}
1005 		p = skipwhite(p);
1006 	    }
1007 
1008 	    // Optionally get the second index [ :expr].
1009 	    if (*p == ':')
1010 	    {
1011 		if (lp->ll_tv->v_type == VAR_DICT)
1012 		{
1013 		    if (!quiet)
1014 			emsg(_(e_cannot_slice_dictionary));
1015 		    clear_tv(&var1);
1016 		    return NULL;
1017 		}
1018 		if (rettv != NULL
1019 			&& !(rettv->v_type == VAR_LIST
1020 						 && rettv->vval.v_list != NULL)
1021 			&& !(rettv->v_type == VAR_BLOB
1022 						&& rettv->vval.v_blob != NULL))
1023 		{
1024 		    if (!quiet)
1025 			emsg(_("E709: [:] requires a List or Blob value"));
1026 		    clear_tv(&var1);
1027 		    return NULL;
1028 		}
1029 		p = skipwhite(p + 1);
1030 		if (*p == ']')
1031 		    lp->ll_empty2 = TRUE;
1032 		else
1033 		{
1034 		    lp->ll_empty2 = FALSE;
1035 		    // recursive!
1036 		    if (eval1(&p, &var2, &EVALARG_EVALUATE) == FAIL)
1037 		    {
1038 			clear_tv(&var1);
1039 			return NULL;
1040 		    }
1041 		    if (tv_get_string_chk(&var2) == NULL)
1042 		    {
1043 			// not a number or string
1044 			clear_tv(&var1);
1045 			clear_tv(&var2);
1046 			return NULL;
1047 		    }
1048 		}
1049 		lp->ll_range = TRUE;
1050 	    }
1051 	    else
1052 		lp->ll_range = FALSE;
1053 
1054 	    if (*p != ']')
1055 	    {
1056 		if (!quiet)
1057 		    emsg(_(e_missbrac));
1058 		clear_tv(&var1);
1059 		clear_tv(&var2);
1060 		return NULL;
1061 	    }
1062 
1063 	    // Skip to past ']'.
1064 	    ++p;
1065 	}
1066 
1067 	if (lp->ll_tv->v_type == VAR_DICT)
1068 	{
1069 	    if (len == -1)
1070 	    {
1071 		// "[key]": get key from "var1"
1072 		key = tv_get_string_chk(&var1);	// is number or string
1073 		if (key == NULL)
1074 		{
1075 		    clear_tv(&var1);
1076 		    return NULL;
1077 		}
1078 	    }
1079 	    lp->ll_list = NULL;
1080 
1081 	    // a NULL dict is equivalent with an empty dict
1082 	    if (lp->ll_tv->vval.v_dict == NULL)
1083 	    {
1084 		lp->ll_tv->vval.v_dict = dict_alloc();
1085 		if (lp->ll_tv->vval.v_dict == NULL)
1086 		{
1087 		    clear_tv(&var1);
1088 		    return NULL;
1089 		}
1090 		++lp->ll_tv->vval.v_dict->dv_refcount;
1091 	    }
1092 	    lp->ll_dict = lp->ll_tv->vval.v_dict;
1093 
1094 	    lp->ll_di = dict_find(lp->ll_dict, key, len);
1095 
1096 	    // When assigning to a scope dictionary check that a function and
1097 	    // variable name is valid (only variable name unless it is l: or
1098 	    // g: dictionary). Disallow overwriting a builtin function.
1099 	    if (rettv != NULL && lp->ll_dict->dv_scope != 0)
1100 	    {
1101 		int prevval;
1102 		int wrong;
1103 
1104 		if (len != -1)
1105 		{
1106 		    prevval = key[len];
1107 		    key[len] = NUL;
1108 		}
1109 		else
1110 		    prevval = 0; // avoid compiler warning
1111 		wrong = (lp->ll_dict->dv_scope == VAR_DEF_SCOPE
1112 			       && rettv->v_type == VAR_FUNC
1113 			       && var_wrong_func_name(key, lp->ll_di == NULL))
1114 			|| !valid_varname(key, TRUE);
1115 		if (len != -1)
1116 		    key[len] = prevval;
1117 		if (wrong)
1118 		{
1119 		    clear_tv(&var1);
1120 		    return NULL;
1121 		}
1122 	    }
1123 
1124 	    if (lp->ll_valtype != NULL)
1125 		// use the type of the member
1126 		lp->ll_valtype = lp->ll_valtype->tt_member;
1127 
1128 	    if (lp->ll_di == NULL)
1129 	    {
1130 		// Can't add "v:" or "a:" variable.
1131 		if (lp->ll_dict == get_vimvar_dict()
1132 			 || &lp->ll_dict->dv_hashtab == get_funccal_args_ht())
1133 		{
1134 		    semsg(_(e_illvar), name);
1135 		    clear_tv(&var1);
1136 		    return NULL;
1137 		}
1138 
1139 		// Key does not exist in dict: may need to add it.
1140 		if (*p == '[' || *p == '.' || unlet)
1141 		{
1142 		    if (!quiet)
1143 			semsg(_(e_dictkey), key);
1144 		    clear_tv(&var1);
1145 		    return NULL;
1146 		}
1147 		if (len == -1)
1148 		    lp->ll_newkey = vim_strsave(key);
1149 		else
1150 		    lp->ll_newkey = vim_strnsave(key, len);
1151 		clear_tv(&var1);
1152 		if (lp->ll_newkey == NULL)
1153 		    p = NULL;
1154 		break;
1155 	    }
1156 	    // existing variable, need to check if it can be changed
1157 	    else if ((flags & GLV_READ_ONLY) == 0
1158 			&& (var_check_ro(lp->ll_di->di_flags, name, FALSE)
1159 			  || var_check_lock(lp->ll_di->di_flags, name, FALSE)))
1160 	    {
1161 		clear_tv(&var1);
1162 		return NULL;
1163 	    }
1164 
1165 	    clear_tv(&var1);
1166 	    lp->ll_tv = &lp->ll_di->di_tv;
1167 	}
1168 	else if (lp->ll_tv->v_type == VAR_BLOB)
1169 	{
1170 	    long bloblen = blob_len(lp->ll_tv->vval.v_blob);
1171 
1172 	    /*
1173 	     * Get the number and item for the only or first index of the List.
1174 	     */
1175 	    if (empty1)
1176 		lp->ll_n1 = 0;
1177 	    else
1178 		// is number or string
1179 		lp->ll_n1 = (long)tv_get_number(&var1);
1180 	    clear_tv(&var1);
1181 
1182 	    if (check_blob_index(bloblen, lp->ll_n1, quiet) == FAIL)
1183 	    {
1184 		clear_tv(&var2);
1185 		return NULL;
1186 	    }
1187 	    if (lp->ll_range && !lp->ll_empty2)
1188 	    {
1189 		lp->ll_n2 = (long)tv_get_number(&var2);
1190 		clear_tv(&var2);
1191 		if (check_blob_range(bloblen, lp->ll_n1, lp->ll_n2, quiet)
1192 								       == FAIL)
1193 		    return NULL;
1194 	    }
1195 	    lp->ll_blob = lp->ll_tv->vval.v_blob;
1196 	    lp->ll_tv = NULL;
1197 	    break;
1198 	}
1199 	else
1200 	{
1201 	    /*
1202 	     * Get the number and item for the only or first index of the List.
1203 	     */
1204 	    if (empty1)
1205 		lp->ll_n1 = 0;
1206 	    else
1207 		// is number or string
1208 		lp->ll_n1 = (long)tv_get_number(&var1);
1209 	    clear_tv(&var1);
1210 
1211 	    lp->ll_dict = NULL;
1212 	    lp->ll_list = lp->ll_tv->vval.v_list;
1213 	    lp->ll_li = list_find_index(lp->ll_list, &lp->ll_n1);
1214 	    if (lp->ll_li == NULL)
1215 	    {
1216 		// Vim9: Allow for adding an item at the end.
1217 		if (in_vim9script() && lp->ll_n1 == lp->ll_list->lv_len
1218 						  && lp->ll_list->lv_lock == 0)
1219 		{
1220 		    list_append_number(lp->ll_list, 0);
1221 		    lp->ll_li = list_find_index(lp->ll_list, &lp->ll_n1);
1222 		}
1223 		if (lp->ll_li == NULL)
1224 		{
1225 		    clear_tv(&var2);
1226 		    if (!quiet)
1227 			semsg(_(e_listidx), lp->ll_n1);
1228 		    return NULL;
1229 		}
1230 	    }
1231 
1232 	    if (lp->ll_valtype != NULL)
1233 		// use the type of the member
1234 		lp->ll_valtype = lp->ll_valtype->tt_member;
1235 
1236 	    /*
1237 	     * May need to find the item or absolute index for the second
1238 	     * index of a range.
1239 	     * When no index given: "lp->ll_empty2" is TRUE.
1240 	     * Otherwise "lp->ll_n2" is set to the second index.
1241 	     */
1242 	    if (lp->ll_range && !lp->ll_empty2)
1243 	    {
1244 		lp->ll_n2 = (long)tv_get_number(&var2);
1245 						    // is number or string
1246 		clear_tv(&var2);
1247 		if (lp->ll_n2 < 0)
1248 		{
1249 		    ni = list_find(lp->ll_list, lp->ll_n2);
1250 		    if (ni == NULL)
1251 		    {
1252 			if (!quiet)
1253 			    semsg(_(e_listidx), lp->ll_n2);
1254 			return NULL;
1255 		    }
1256 		    lp->ll_n2 = list_idx_of_item(lp->ll_list, ni);
1257 		}
1258 
1259 		// Check that lp->ll_n2 isn't before lp->ll_n1.
1260 		if (lp->ll_n1 < 0)
1261 		    lp->ll_n1 = list_idx_of_item(lp->ll_list, lp->ll_li);
1262 		if (lp->ll_n2 < lp->ll_n1)
1263 		{
1264 		    if (!quiet)
1265 			semsg(_(e_listidx), lp->ll_n2);
1266 		    return NULL;
1267 		}
1268 	    }
1269 
1270 	    lp->ll_tv = &lp->ll_li->li_tv;
1271 	}
1272     }
1273 
1274     clear_tv(&var1);
1275     lp->ll_name_end = p;
1276     return p;
1277 }
1278 
1279 /*
1280  * Clear lval "lp" that was filled by get_lval().
1281  */
1282     void
1283 clear_lval(lval_T *lp)
1284 {
1285     vim_free(lp->ll_exp_name);
1286     vim_free(lp->ll_newkey);
1287 }
1288 
1289 /*
1290  * Set a variable that was parsed by get_lval() to "rettv".
1291  * "endp" points to just after the parsed name.
1292  * "op" is NULL, "+" for "+=", "-" for "-=", "*" for "*=", "/" for "/=",
1293  * "%" for "%=", "." for ".=" or "=" for "=".
1294  */
1295     void
1296 set_var_lval(
1297     lval_T	*lp,
1298     char_u	*endp,
1299     typval_T	*rettv,
1300     int		copy,
1301     int		flags,	    // ASSIGN_CONST, ASSIGN_NO_DECL
1302     char_u	*op,
1303     int		var_idx)    // index for "let [a, b] = list"
1304 {
1305     int		cc;
1306     listitem_T	*ri;
1307     dictitem_T	*di;
1308 
1309     if (lp->ll_tv == NULL)
1310     {
1311 	cc = *endp;
1312 	*endp = NUL;
1313 	if (in_vim9script() && check_reserved_name(lp->ll_name) == FAIL)
1314 	    return;
1315 
1316 	if (lp->ll_blob != NULL)
1317 	{
1318 	    int	    error = FALSE, val;
1319 
1320 	    if (op != NULL && *op != '=')
1321 	    {
1322 		semsg(_(e_letwrong), op);
1323 		return;
1324 	    }
1325 	    if (value_check_lock(lp->ll_blob->bv_lock, lp->ll_name, FALSE))
1326 		return;
1327 
1328 	    if (lp->ll_range && rettv->v_type == VAR_BLOB)
1329 	    {
1330 		if (lp->ll_empty2)
1331 		    lp->ll_n2 = blob_len(lp->ll_blob) - 1;
1332 
1333 		if (blob_set_range(lp->ll_blob, lp->ll_n1, lp->ll_n2,
1334 								rettv) == FAIL)
1335 		    return;
1336 	    }
1337 	    else
1338 	    {
1339 		val = (int)tv_get_number_chk(rettv, &error);
1340 		if (!error)
1341 		    blob_set_append(lp->ll_blob, lp->ll_n1, val);
1342 	    }
1343 	}
1344 	else if (op != NULL && *op != '=')
1345 	{
1346 	    typval_T tv;
1347 
1348 	    if ((flags & (ASSIGN_CONST | ASSIGN_FINAL))
1349 					     && (flags & ASSIGN_FOR_LOOP) == 0)
1350 	    {
1351 		emsg(_(e_cannot_mod));
1352 		*endp = cc;
1353 		return;
1354 	    }
1355 
1356 	    // handle +=, -=, *=, /=, %= and .=
1357 	    di = NULL;
1358 	    if (eval_variable(lp->ll_name, (int)STRLEN(lp->ll_name),
1359 					     &tv, &di, EVAL_VAR_VERBOSE) == OK)
1360 	    {
1361 		if ((di == NULL
1362 			 || (!var_check_ro(di->di_flags, lp->ll_name, FALSE)
1363 			   && !tv_check_lock(&di->di_tv, lp->ll_name, FALSE)))
1364 			&& tv_op(&tv, rettv, op) == OK)
1365 		    set_var_const(lp->ll_name, NULL, &tv, FALSE,
1366 							    ASSIGN_NO_DECL, 0);
1367 		clear_tv(&tv);
1368 	    }
1369 	}
1370 	else
1371 	{
1372 	    if (lp->ll_type != NULL && check_typval_arg_type(lp->ll_type, rettv,
1373 							      NULL, 0) == FAIL)
1374 		return;
1375 	    set_var_const(lp->ll_name, lp->ll_type, rettv, copy,
1376 							       flags, var_idx);
1377 	}
1378 	*endp = cc;
1379     }
1380     else if (value_check_lock(lp->ll_newkey == NULL
1381 		? lp->ll_tv->v_lock
1382 		: lp->ll_tv->vval.v_dict->dv_lock, lp->ll_name, FALSE))
1383 	;
1384     else if (lp->ll_range)
1385     {
1386 	listitem_T *ll_li = lp->ll_li;
1387 	int	    ll_n1 = lp->ll_n1;
1388 
1389 	if ((flags & (ASSIGN_CONST | ASSIGN_FINAL))
1390 					     && (flags & ASSIGN_FOR_LOOP) == 0)
1391 	{
1392 	    emsg(_("E996: Cannot lock a range"));
1393 	    return;
1394 	}
1395 
1396 	/*
1397 	 * Check whether any of the list items is locked
1398 	 */
1399 	for (ri = rettv->vval.v_list->lv_first; ri != NULL && ll_li != NULL; )
1400 	{
1401 	    if (value_check_lock(ll_li->li_tv.v_lock, lp->ll_name, FALSE))
1402 		return;
1403 	    ri = ri->li_next;
1404 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == ll_n1))
1405 		break;
1406 	    ll_li = ll_li->li_next;
1407 	    ++ll_n1;
1408 	}
1409 
1410 	/*
1411 	 * Assign the List values to the list items.
1412 	 */
1413 	for (ri = rettv->vval.v_list->lv_first; ri != NULL; )
1414 	{
1415 	    if (op != NULL && *op != '=')
1416 		tv_op(&lp->ll_li->li_tv, &ri->li_tv, op);
1417 	    else
1418 	    {
1419 		clear_tv(&lp->ll_li->li_tv);
1420 		copy_tv(&ri->li_tv, &lp->ll_li->li_tv);
1421 	    }
1422 	    ri = ri->li_next;
1423 	    if (ri == NULL || (!lp->ll_empty2 && lp->ll_n2 == lp->ll_n1))
1424 		break;
1425 	    if (lp->ll_li->li_next == NULL)
1426 	    {
1427 		// Need to add an empty item.
1428 		if (list_append_number(lp->ll_list, 0) == FAIL)
1429 		{
1430 		    ri = NULL;
1431 		    break;
1432 		}
1433 	    }
1434 	    lp->ll_li = lp->ll_li->li_next;
1435 	    ++lp->ll_n1;
1436 	}
1437 	if (ri != NULL)
1438 	    emsg(_(e_list_value_has_more_items_than_targets));
1439 	else if (lp->ll_empty2
1440 		? (lp->ll_li != NULL && lp->ll_li->li_next != NULL)
1441 		: lp->ll_n1 != lp->ll_n2)
1442 	    emsg(_(e_list_value_does_not_have_enough_items));
1443     }
1444     else
1445     {
1446 	/*
1447 	 * Assign to a List or Dictionary item.
1448 	 */
1449 	if ((flags & (ASSIGN_CONST | ASSIGN_FINAL))
1450 					     && (flags & ASSIGN_FOR_LOOP) == 0)
1451 	{
1452 	    emsg(_("E996: Cannot lock a list or dict"));
1453 	    return;
1454 	}
1455 
1456 	if (lp->ll_valtype != NULL
1457 		    && check_typval_arg_type(lp->ll_valtype, rettv,
1458 							      NULL, 0) == FAIL)
1459 	    return;
1460 
1461 	if (lp->ll_newkey != NULL)
1462 	{
1463 	    if (op != NULL && *op != '=')
1464 	    {
1465 		semsg(_(e_dictkey), lp->ll_newkey);
1466 		return;
1467 	    }
1468 	    if (dict_wrong_func_name(lp->ll_tv->vval.v_dict, rettv,
1469 								lp->ll_newkey))
1470 		return;
1471 
1472 	    // Need to add an item to the Dictionary.
1473 	    di = dictitem_alloc(lp->ll_newkey);
1474 	    if (di == NULL)
1475 		return;
1476 	    if (dict_add(lp->ll_tv->vval.v_dict, di) == FAIL)
1477 	    {
1478 		vim_free(di);
1479 		return;
1480 	    }
1481 	    lp->ll_tv = &di->di_tv;
1482 	}
1483 	else if (op != NULL && *op != '=')
1484 	{
1485 	    tv_op(lp->ll_tv, rettv, op);
1486 	    return;
1487 	}
1488 	else
1489 	    clear_tv(lp->ll_tv);
1490 
1491 	/*
1492 	 * Assign the value to the variable or list item.
1493 	 */
1494 	if (copy)
1495 	    copy_tv(rettv, lp->ll_tv);
1496 	else
1497 	{
1498 	    *lp->ll_tv = *rettv;
1499 	    lp->ll_tv->v_lock = 0;
1500 	    init_tv(rettv);
1501 	}
1502     }
1503 }
1504 
1505 /*
1506  * Handle "tv1 += tv2", "tv1 -= tv2", "tv1 *= tv2", "tv1 /= tv2", "tv1 %= tv2"
1507  * and "tv1 .= tv2"
1508  * Returns OK or FAIL.
1509  */
1510     static int
1511 tv_op(typval_T *tv1, typval_T *tv2, char_u *op)
1512 {
1513     varnumber_T	n;
1514     char_u	numbuf[NUMBUFLEN];
1515     char_u	*s;
1516     int		failed = FALSE;
1517 
1518     // Can't do anything with a Funcref, Dict, v:true on the right.
1519     if (tv2->v_type != VAR_FUNC && tv2->v_type != VAR_DICT
1520 		      && tv2->v_type != VAR_BOOL && tv2->v_type != VAR_SPECIAL)
1521     {
1522 	switch (tv1->v_type)
1523 	{
1524 	    case VAR_UNKNOWN:
1525 	    case VAR_ANY:
1526 	    case VAR_VOID:
1527 	    case VAR_DICT:
1528 	    case VAR_FUNC:
1529 	    case VAR_PARTIAL:
1530 	    case VAR_BOOL:
1531 	    case VAR_SPECIAL:
1532 	    case VAR_JOB:
1533 	    case VAR_CHANNEL:
1534 	    case VAR_INSTR:
1535 		break;
1536 
1537 	    case VAR_BLOB:
1538 		if (*op != '+' || tv2->v_type != VAR_BLOB)
1539 		    break;
1540 		// BLOB += BLOB
1541 		if (tv1->vval.v_blob != NULL && tv2->vval.v_blob != NULL)
1542 		{
1543 		    blob_T  *b1 = tv1->vval.v_blob;
1544 		    blob_T  *b2 = tv2->vval.v_blob;
1545 		    int	i, len = blob_len(b2);
1546 		    for (i = 0; i < len; i++)
1547 			ga_append(&b1->bv_ga, blob_get(b2, i));
1548 		}
1549 		return OK;
1550 
1551 	    case VAR_LIST:
1552 		if (*op != '+' || tv2->v_type != VAR_LIST)
1553 		    break;
1554 		// List += List
1555 		if (tv2->vval.v_list != NULL)
1556 		{
1557 		    if (tv1->vval.v_list == NULL)
1558 		    {
1559 			tv1->vval.v_list = tv2->vval.v_list;
1560 			++tv1->vval.v_list->lv_refcount;
1561 		    }
1562 		    else
1563 			list_extend(tv1->vval.v_list, tv2->vval.v_list, NULL);
1564 		}
1565 		return OK;
1566 
1567 	    case VAR_NUMBER:
1568 	    case VAR_STRING:
1569 		if (tv2->v_type == VAR_LIST)
1570 		    break;
1571 		if (vim_strchr((char_u *)"+-*/%", *op) != NULL)
1572 		{
1573 		    // nr += nr , nr -= nr , nr *=nr , nr /= nr , nr %= nr
1574 		    n = tv_get_number(tv1);
1575 #ifdef FEAT_FLOAT
1576 		    if (tv2->v_type == VAR_FLOAT)
1577 		    {
1578 			float_T f = n;
1579 
1580 			if (*op == '%')
1581 			    break;
1582 			switch (*op)
1583 			{
1584 			    case '+': f += tv2->vval.v_float; break;
1585 			    case '-': f -= tv2->vval.v_float; break;
1586 			    case '*': f *= tv2->vval.v_float; break;
1587 			    case '/': f /= tv2->vval.v_float; break;
1588 			}
1589 			clear_tv(tv1);
1590 			tv1->v_type = VAR_FLOAT;
1591 			tv1->vval.v_float = f;
1592 		    }
1593 		    else
1594 #endif
1595 		    {
1596 			switch (*op)
1597 			{
1598 			    case '+': n += tv_get_number(tv2); break;
1599 			    case '-': n -= tv_get_number(tv2); break;
1600 			    case '*': n *= tv_get_number(tv2); break;
1601 			    case '/': n = num_divide(n, tv_get_number(tv2),
1602 							       &failed); break;
1603 			    case '%': n = num_modulus(n, tv_get_number(tv2),
1604 							       &failed); break;
1605 			}
1606 			clear_tv(tv1);
1607 			tv1->v_type = VAR_NUMBER;
1608 			tv1->vval.v_number = n;
1609 		    }
1610 		}
1611 		else
1612 		{
1613 		    if (tv2->v_type == VAR_FLOAT)
1614 			break;
1615 
1616 		    // str .= str
1617 		    s = tv_get_string(tv1);
1618 		    s = concat_str(s, tv_get_string_buf(tv2, numbuf));
1619 		    clear_tv(tv1);
1620 		    tv1->v_type = VAR_STRING;
1621 		    tv1->vval.v_string = s;
1622 		}
1623 		return failed ? FAIL : OK;
1624 
1625 	    case VAR_FLOAT:
1626 #ifdef FEAT_FLOAT
1627 		{
1628 		    float_T f;
1629 
1630 		    if (*op == '%' || *op == '.'
1631 				   || (tv2->v_type != VAR_FLOAT
1632 				    && tv2->v_type != VAR_NUMBER
1633 				    && tv2->v_type != VAR_STRING))
1634 			break;
1635 		    if (tv2->v_type == VAR_FLOAT)
1636 			f = tv2->vval.v_float;
1637 		    else
1638 			f = tv_get_number(tv2);
1639 		    switch (*op)
1640 		    {
1641 			case '+': tv1->vval.v_float += f; break;
1642 			case '-': tv1->vval.v_float -= f; break;
1643 			case '*': tv1->vval.v_float *= f; break;
1644 			case '/': tv1->vval.v_float /= f; break;
1645 		    }
1646 		}
1647 #endif
1648 		return OK;
1649 	}
1650     }
1651 
1652     semsg(_(e_letwrong), op);
1653     return FAIL;
1654 }
1655 
1656 /*
1657  * Evaluate the expression used in a ":for var in expr" command.
1658  * "arg" points to "var".
1659  * Set "*errp" to TRUE for an error, FALSE otherwise;
1660  * Return a pointer that holds the info.  Null when there is an error.
1661  */
1662     void *
1663 eval_for_line(
1664     char_u	*arg,
1665     int		*errp,
1666     exarg_T	*eap,
1667     evalarg_T	*evalarg)
1668 {
1669     forinfo_T	*fi;
1670     char_u	*var_list_end;
1671     char_u	*expr;
1672     typval_T	tv;
1673     list_T	*l;
1674     int		skip = !(evalarg->eval_flags & EVAL_EVALUATE);
1675 
1676     *errp = TRUE;	// default: there is an error
1677 
1678     fi = ALLOC_CLEAR_ONE(forinfo_T);
1679     if (fi == NULL)
1680 	return NULL;
1681 
1682     var_list_end = skip_var_list(arg, TRUE, &fi->fi_varcount,
1683 						     &fi->fi_semicolon, FALSE);
1684     if (var_list_end == NULL)
1685 	return fi;
1686 
1687     expr = skipwhite_and_linebreak(var_list_end, evalarg);
1688     if (expr[0] != 'i' || expr[1] != 'n'
1689 				  || !(expr[2] == NUL || VIM_ISWHITE(expr[2])))
1690     {
1691 	if (in_vim9script() && *expr == ':' && expr != var_list_end)
1692 	    semsg(_(e_no_white_space_allowed_before_colon_str), expr);
1693 	else
1694 	    emsg(_(e_missing_in));
1695 	return fi;
1696     }
1697 
1698     if (skip)
1699 	++emsg_skip;
1700     expr = skipwhite_and_linebreak(expr + 2, evalarg);
1701     if (eval0(expr, &tv, eap, evalarg) == OK)
1702     {
1703 	*errp = FALSE;
1704 	if (!skip)
1705 	{
1706 	    if (tv.v_type == VAR_LIST)
1707 	    {
1708 		l = tv.vval.v_list;
1709 		if (l == NULL)
1710 		{
1711 		    // a null list is like an empty list: do nothing
1712 		    clear_tv(&tv);
1713 		}
1714 		else
1715 		{
1716 		    // Need a real list here.
1717 		    CHECK_LIST_MATERIALIZE(l);
1718 
1719 		    // No need to increment the refcount, it's already set for
1720 		    // the list being used in "tv".
1721 		    fi->fi_list = l;
1722 		    list_add_watch(l, &fi->fi_lw);
1723 		    fi->fi_lw.lw_item = l->lv_first;
1724 		}
1725 	    }
1726 	    else if (tv.v_type == VAR_BLOB)
1727 	    {
1728 		fi->fi_bi = 0;
1729 		if (tv.vval.v_blob != NULL)
1730 		{
1731 		    typval_T btv;
1732 
1733 		    // Make a copy, so that the iteration still works when the
1734 		    // blob is changed.
1735 		    blob_copy(tv.vval.v_blob, &btv);
1736 		    fi->fi_blob = btv.vval.v_blob;
1737 		}
1738 		clear_tv(&tv);
1739 	    }
1740 	    else if (tv.v_type == VAR_STRING)
1741 	    {
1742 		fi->fi_byte_idx = 0;
1743 		fi->fi_string = tv.vval.v_string;
1744 		tv.vval.v_string = NULL;
1745 		if (fi->fi_string == NULL)
1746 		    fi->fi_string = vim_strsave((char_u *)"");
1747 	    }
1748 	    else
1749 	    {
1750 		emsg(_(e_listreq));
1751 		clear_tv(&tv);
1752 	    }
1753 	}
1754     }
1755     if (skip)
1756 	--emsg_skip;
1757     fi->fi_break_count = evalarg->eval_break_count;
1758 
1759     return fi;
1760 }
1761 
1762 /*
1763  * Used when looping over a :for line, skip the "in expr" part.
1764  */
1765     void
1766 skip_for_lines(void *fi_void, evalarg_T *evalarg)
1767 {
1768     forinfo_T	*fi = (forinfo_T *)fi_void;
1769     int		i;
1770 
1771     for (i = 0; i < fi->fi_break_count; ++i)
1772 	eval_next_line(evalarg);
1773 }
1774 
1775 /*
1776  * Use the first item in a ":for" list.  Advance to the next.
1777  * Assign the values to the variable (list).  "arg" points to the first one.
1778  * Return TRUE when a valid item was found, FALSE when at end of list or
1779  * something wrong.
1780  */
1781     int
1782 next_for_item(void *fi_void, char_u *arg)
1783 {
1784     forinfo_T	*fi = (forinfo_T *)fi_void;
1785     int		result;
1786     int		flag = ASSIGN_FOR_LOOP | (in_vim9script()
1787 			 ? (ASSIGN_FINAL
1788 			     // first round: error if variable exists
1789 			     | (fi->fi_bi == 0 ? 0 : ASSIGN_DECL)
1790 			     | ASSIGN_NO_MEMBER_TYPE)
1791 			 : 0);
1792     listitem_T	*item;
1793     int		skip_assign = in_vim9script() && arg[0] == '_'
1794 						      && !eval_isnamec(arg[1]);
1795 
1796     if (fi->fi_blob != NULL)
1797     {
1798 	typval_T	tv;
1799 
1800 	if (fi->fi_bi >= blob_len(fi->fi_blob))
1801 	    return FALSE;
1802 	tv.v_type = VAR_NUMBER;
1803 	tv.v_lock = VAR_FIXED;
1804 	tv.vval.v_number = blob_get(fi->fi_blob, fi->fi_bi);
1805 	++fi->fi_bi;
1806 	if (skip_assign)
1807 	    return TRUE;
1808 	return ex_let_vars(arg, &tv, TRUE, fi->fi_semicolon,
1809 					    fi->fi_varcount, flag, NULL) == OK;
1810     }
1811 
1812     if (fi->fi_string != NULL)
1813     {
1814 	typval_T	tv;
1815 	int		len;
1816 
1817 	len = mb_ptr2len(fi->fi_string + fi->fi_byte_idx);
1818 	if (len == 0)
1819 	    return FALSE;
1820 	tv.v_type = VAR_STRING;
1821 	tv.v_lock = VAR_FIXED;
1822 	tv.vval.v_string = vim_strnsave(fi->fi_string + fi->fi_byte_idx, len);
1823 	fi->fi_byte_idx += len;
1824 	++fi->fi_bi;
1825 	if (skip_assign)
1826 	    result = TRUE;
1827 	else
1828 	    result = ex_let_vars(arg, &tv, TRUE, fi->fi_semicolon,
1829 					    fi->fi_varcount, flag, NULL) == OK;
1830 	vim_free(tv.vval.v_string);
1831 	return result;
1832     }
1833 
1834     item = fi->fi_lw.lw_item;
1835     if (item == NULL)
1836 	result = FALSE;
1837     else
1838     {
1839 	fi->fi_lw.lw_item = item->li_next;
1840 	++fi->fi_bi;
1841 	if (skip_assign)
1842 	    result = TRUE;
1843 	else
1844 	    result = (ex_let_vars(arg, &item->li_tv, TRUE, fi->fi_semicolon,
1845 					   fi->fi_varcount, flag, NULL) == OK);
1846     }
1847     return result;
1848 }
1849 
1850 /*
1851  * Free the structure used to store info used by ":for".
1852  */
1853     void
1854 free_for_info(void *fi_void)
1855 {
1856     forinfo_T    *fi = (forinfo_T *)fi_void;
1857 
1858     if (fi == NULL)
1859 	return;
1860     if (fi->fi_list != NULL)
1861     {
1862 	list_rem_watch(fi->fi_list, &fi->fi_lw);
1863 	list_unref(fi->fi_list);
1864     }
1865     else if (fi->fi_blob != NULL)
1866 	blob_unref(fi->fi_blob);
1867     else
1868 	vim_free(fi->fi_string);
1869     vim_free(fi);
1870 }
1871 
1872     void
1873 set_context_for_expression(
1874     expand_T	*xp,
1875     char_u	*arg,
1876     cmdidx_T	cmdidx)
1877 {
1878     int		has_expr = cmdidx != CMD_let && cmdidx != CMD_var;
1879     int		c;
1880     char_u	*p;
1881 
1882     if (cmdidx == CMD_let || cmdidx == CMD_var
1883 				 || cmdidx == CMD_const || cmdidx == CMD_final)
1884     {
1885 	xp->xp_context = EXPAND_USER_VARS;
1886 	if (vim_strpbrk(arg, (char_u *)"\"'+-*/%.=!?~|&$([<>,#") == NULL)
1887 	{
1888 	    // ":let var1 var2 ...": find last space.
1889 	    for (p = arg + STRLEN(arg); p >= arg; )
1890 	    {
1891 		xp->xp_pattern = p;
1892 		MB_PTR_BACK(arg, p);
1893 		if (VIM_ISWHITE(*p))
1894 		    break;
1895 	    }
1896 	    return;
1897 	}
1898     }
1899     else
1900 	xp->xp_context = cmdidx == CMD_call ? EXPAND_FUNCTIONS
1901 							  : EXPAND_EXPRESSION;
1902     while ((xp->xp_pattern = vim_strpbrk(arg,
1903 				  (char_u *)"\"'+-*/%.=!?~|&$([<>,#")) != NULL)
1904     {
1905 	c = *xp->xp_pattern;
1906 	if (c == '&')
1907 	{
1908 	    c = xp->xp_pattern[1];
1909 	    if (c == '&')
1910 	    {
1911 		++xp->xp_pattern;
1912 		xp->xp_context = has_expr ? EXPAND_EXPRESSION : EXPAND_NOTHING;
1913 	    }
1914 	    else if (c != ' ')
1915 	    {
1916 		xp->xp_context = EXPAND_SETTINGS;
1917 		if ((c == 'l' || c == 'g') && xp->xp_pattern[2] == ':')
1918 		    xp->xp_pattern += 2;
1919 
1920 	    }
1921 	}
1922 	else if (c == '$')
1923 	{
1924 	    // environment variable
1925 	    xp->xp_context = EXPAND_ENV_VARS;
1926 	}
1927 	else if (c == '=')
1928 	{
1929 	    has_expr = TRUE;
1930 	    xp->xp_context = EXPAND_EXPRESSION;
1931 	}
1932 	else if (c == '#'
1933 		&& xp->xp_context == EXPAND_EXPRESSION)
1934 	{
1935 	    // Autoload function/variable contains '#'.
1936 	    break;
1937 	}
1938 	else if ((c == '<' || c == '#')
1939 		&& xp->xp_context == EXPAND_FUNCTIONS
1940 		&& vim_strchr(xp->xp_pattern, '(') == NULL)
1941 	{
1942 	    // Function name can start with "<SNR>" and contain '#'.
1943 	    break;
1944 	}
1945 	else if (has_expr)
1946 	{
1947 	    if (c == '"')	    // string
1948 	    {
1949 		while ((c = *++xp->xp_pattern) != NUL && c != '"')
1950 		    if (c == '\\' && xp->xp_pattern[1] != NUL)
1951 			++xp->xp_pattern;
1952 		xp->xp_context = EXPAND_NOTHING;
1953 	    }
1954 	    else if (c == '\'')	    // literal string
1955 	    {
1956 		// Trick: '' is like stopping and starting a literal string.
1957 		while ((c = *++xp->xp_pattern) != NUL && c != '\'')
1958 		    /* skip */ ;
1959 		xp->xp_context = EXPAND_NOTHING;
1960 	    }
1961 	    else if (c == '|')
1962 	    {
1963 		if (xp->xp_pattern[1] == '|')
1964 		{
1965 		    ++xp->xp_pattern;
1966 		    xp->xp_context = EXPAND_EXPRESSION;
1967 		}
1968 		else
1969 		    xp->xp_context = EXPAND_COMMANDS;
1970 	    }
1971 	    else
1972 		xp->xp_context = EXPAND_EXPRESSION;
1973 	}
1974 	else
1975 	    // Doesn't look like something valid, expand as an expression
1976 	    // anyway.
1977 	    xp->xp_context = EXPAND_EXPRESSION;
1978 	arg = xp->xp_pattern;
1979 	if (*arg != NUL)
1980 	    while ((c = *++arg) != NUL && (c == ' ' || c == '\t'))
1981 		/* skip */ ;
1982     }
1983 
1984     // ":exe one two" completes "two"
1985     if ((cmdidx == CMD_execute
1986 		|| cmdidx == CMD_echo
1987 		|| cmdidx == CMD_echon
1988 		|| cmdidx == CMD_echomsg)
1989 	    && xp->xp_context == EXPAND_EXPRESSION)
1990     {
1991 	for (;;)
1992 	{
1993 	    char_u *n = skiptowhite(arg);
1994 
1995 	    if (n == arg || IS_WHITE_OR_NUL(*skipwhite(n)))
1996 		break;
1997 	    arg = skipwhite(n);
1998 	}
1999     }
2000 
2001     xp->xp_pattern = arg;
2002 }
2003 
2004 /*
2005  * Return TRUE if "pat" matches "text".
2006  * Does not use 'cpo' and always uses 'magic'.
2007  */
2008     int
2009 pattern_match(char_u *pat, char_u *text, int ic)
2010 {
2011     int		matches = FALSE;
2012     char_u	*save_cpo;
2013     regmatch_T	regmatch;
2014 
2015     // avoid 'l' flag in 'cpoptions'
2016     save_cpo = p_cpo;
2017     p_cpo = empty_option;
2018     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
2019     if (regmatch.regprog != NULL)
2020     {
2021 	regmatch.rm_ic = ic;
2022 	matches = vim_regexec_nl(&regmatch, text, (colnr_T)0);
2023 	vim_regfree(regmatch.regprog);
2024     }
2025     p_cpo = save_cpo;
2026     return matches;
2027 }
2028 
2029 /*
2030  * Handle a name followed by "(".  Both for just "name(arg)" and for
2031  * "expr->name(arg)".
2032  * Returns OK or FAIL.
2033  */
2034     static int
2035 eval_func(
2036 	char_u	    **arg,	// points to "(", will be advanced
2037 	evalarg_T   *evalarg,
2038 	char_u	    *name,
2039 	int	    name_len,
2040 	typval_T    *rettv,
2041 	int	    flags,
2042 	typval_T    *basetv)	// "expr" for "expr->name(arg)"
2043 {
2044     int		evaluate = flags & EVAL_EVALUATE;
2045     char_u	*s = name;
2046     int		len = name_len;
2047     partial_T	*partial;
2048     int		ret = OK;
2049     type_T	*type = NULL;
2050 
2051     if (!evaluate)
2052 	check_vars(s, len);
2053 
2054     // If "s" is the name of a variable of type VAR_FUNC
2055     // use its contents.
2056     s = deref_func_name(s, &len, &partial,
2057 				    in_vim9script() ? &type : NULL, !evaluate);
2058 
2059     // Need to make a copy, in case evaluating the arguments makes
2060     // the name invalid.
2061     s = vim_strsave(s);
2062     if (s == NULL || (flags & EVAL_CONSTANT))
2063 	ret = FAIL;
2064     else
2065     {
2066 	funcexe_T funcexe;
2067 
2068 	// Invoke the function.
2069 	CLEAR_FIELD(funcexe);
2070 	funcexe.firstline = curwin->w_cursor.lnum;
2071 	funcexe.lastline = curwin->w_cursor.lnum;
2072 	funcexe.evaluate = evaluate;
2073 	funcexe.partial = partial;
2074 	funcexe.basetv = basetv;
2075 	funcexe.check_type = type;
2076 	ret = get_func_tv(s, len, rettv, arg, evalarg, &funcexe);
2077     }
2078     vim_free(s);
2079 
2080     // If evaluate is FALSE rettv->v_type was not set in
2081     // get_func_tv, but it's needed in handle_subscript() to parse
2082     // what follows. So set it here.
2083     if (rettv->v_type == VAR_UNKNOWN && !evaluate && **arg == '(')
2084     {
2085 	rettv->vval.v_string = NULL;
2086 	rettv->v_type = VAR_FUNC;
2087     }
2088 
2089     // Stop the expression evaluation when immediately
2090     // aborting on error, or when an interrupt occurred or
2091     // an exception was thrown but not caught.
2092     if (evaluate && aborting())
2093     {
2094 	if (ret == OK)
2095 	    clear_tv(rettv);
2096 	ret = FAIL;
2097     }
2098     return ret;
2099 }
2100 
2101 /*
2102  * Get the next line source line without advancing.  But do skip over comment
2103  * lines.
2104  * Only called for Vim9 script.
2105  */
2106     static char_u *
2107 getline_peek_skip_comments(evalarg_T *evalarg)
2108 {
2109     for (;;)
2110     {
2111 	char_u *next = getline_peek(evalarg->eval_getline,
2112 							 evalarg->eval_cookie);
2113 	char_u *p;
2114 
2115 	if (next == NULL)
2116 	    break;
2117 	p = skipwhite(next);
2118 	if (*p != NUL && !vim9_comment_start(p))
2119 	    return next;
2120 	(void)eval_next_line(evalarg);
2121     }
2122     return NULL;
2123 }
2124 
2125 /*
2126  * If inside Vim9 script, "arg" points to the end of a line (ignoring a #
2127  * comment) and there is a next line, return the next line (skipping blanks)
2128  * and set "getnext".
2129  * Otherwise return the next non-white at or after "arg" and set "getnext" to
2130  * FALSE.
2131  * "arg" must point somewhere inside a line, not at the start.
2132  */
2133     static char_u *
2134 eval_next_non_blank(char_u *arg, evalarg_T *evalarg, int *getnext)
2135 {
2136     char_u *p = skipwhite(arg);
2137 
2138     *getnext = FALSE;
2139     if (in_vim9script()
2140 	    && evalarg != NULL
2141 	    && (evalarg->eval_cookie != NULL || evalarg->eval_cctx != NULL)
2142 	    && (*p == NUL || (vim9_comment_start(p) && VIM_ISWHITE(p[-1]))))
2143     {
2144 	char_u *next;
2145 
2146 	if (evalarg->eval_cookie != NULL)
2147 	    next = getline_peek_skip_comments(evalarg);
2148 	else
2149 	    next = peek_next_line_from_context(evalarg->eval_cctx);
2150 
2151 	if (next != NULL)
2152 	{
2153 	    *getnext = TRUE;
2154 	    return skipwhite(next);
2155 	}
2156     }
2157     return p;
2158 }
2159 
2160 /*
2161  * To be called after eval_next_non_blank() sets "getnext" to TRUE.
2162  * Only called for Vim9 script.
2163  */
2164     static char_u *
2165 eval_next_line(evalarg_T *evalarg)
2166 {
2167     garray_T	*gap = &evalarg->eval_ga;
2168     char_u	*line;
2169 
2170     if (evalarg->eval_cookie != NULL)
2171 	line = evalarg->eval_getline(0, evalarg->eval_cookie, 0,
2172 							   GETLINE_CONCAT_ALL);
2173     else
2174 	line = next_line_from_context(evalarg->eval_cctx, TRUE);
2175     ++evalarg->eval_break_count;
2176     if (gap->ga_itemsize > 0 && ga_grow(gap, 1) == OK)
2177     {
2178 	char_u *p = skipwhite(line);
2179 
2180 	// Going to concatenate the lines after parsing.  For an empty or
2181 	// comment line use an empty string.
2182 	if (*p == NUL || vim9_comment_start(p))
2183 	{
2184 	    vim_free(line);
2185 	    line = vim_strsave((char_u *)"");
2186 	}
2187 
2188 	((char_u **)gap->ga_data)[gap->ga_len] = line;
2189 	++gap->ga_len;
2190     }
2191     else if (evalarg->eval_cookie != NULL)
2192     {
2193 	vim_free(evalarg->eval_tofree);
2194 	evalarg->eval_tofree = line;
2195     }
2196 
2197     // Advanced to the next line, "arg" no longer points into the previous
2198     // line.
2199     VIM_CLEAR(evalarg->eval_tofree_cmdline);
2200 
2201     return skipwhite(line);
2202 }
2203 
2204 /*
2205  * Call eval_next_non_blank() and get the next line if needed.
2206  */
2207     char_u *
2208 skipwhite_and_linebreak(char_u *arg, evalarg_T *evalarg)
2209 {
2210     int	    getnext;
2211     char_u  *p = skipwhite(arg);
2212 
2213     if (evalarg == NULL)
2214 	return skipwhite(arg);
2215     eval_next_non_blank(p, evalarg, &getnext);
2216     if (getnext)
2217 	return eval_next_line(evalarg);
2218     return p;
2219 }
2220 
2221 /*
2222  * After using "evalarg" filled from "eap": free the memory.
2223  */
2224     void
2225 clear_evalarg(evalarg_T *evalarg, exarg_T *eap)
2226 {
2227     if (evalarg != NULL)
2228     {
2229 	if (evalarg->eval_tofree != NULL)
2230 	{
2231 	    if (eap != NULL)
2232 	    {
2233 		// We may need to keep the original command line, e.g. for
2234 		// ":let" it has the variable names.  But we may also need the
2235 		// new one, "nextcmd" points into it.  Keep both.
2236 		vim_free(eap->cmdline_tofree);
2237 		eap->cmdline_tofree = *eap->cmdlinep;
2238 		*eap->cmdlinep = evalarg->eval_tofree;
2239 	    }
2240 	    else
2241 		vim_free(evalarg->eval_tofree);
2242 	    evalarg->eval_tofree = NULL;
2243 	}
2244 
2245 	VIM_CLEAR(evalarg->eval_tofree_cmdline);
2246 	VIM_CLEAR(evalarg->eval_tofree_lambda);
2247     }
2248 }
2249 
2250 /*
2251  * The "evaluate" argument: When FALSE, the argument is only parsed but not
2252  * executed.  The function may return OK, but the rettv will be of type
2253  * VAR_UNKNOWN.  The function still returns FAIL for a syntax error.
2254  */
2255 
2256 /*
2257  * Handle zero level expression.
2258  * This calls eval1() and handles error message and nextcmd.
2259  * Put the result in "rettv" when returning OK and "evaluate" is TRUE.
2260  * Note: "rettv.v_lock" is not set.
2261  * "evalarg" can be NULL, EVALARG_EVALUATE or a pointer.
2262  * Return OK or FAIL.
2263  */
2264     int
2265 eval0(
2266     char_u	*arg,
2267     typval_T	*rettv,
2268     exarg_T	*eap,
2269     evalarg_T	*evalarg)
2270 {
2271     int		ret;
2272     char_u	*p;
2273     int		did_emsg_before = did_emsg;
2274     int		called_emsg_before = called_emsg;
2275     int		flags = evalarg == NULL ? 0 : evalarg->eval_flags;
2276     int		end_error = FALSE;
2277 
2278     p = skipwhite(arg);
2279     ret = eval1(&p, rettv, evalarg);
2280     p = skipwhite(p);
2281 
2282     if (ret != FAIL)
2283 	end_error = !ends_excmd2(arg, p);
2284     if (ret == FAIL || end_error)
2285     {
2286 	if (ret != FAIL)
2287 	    clear_tv(rettv);
2288 	/*
2289 	 * Report the invalid expression unless the expression evaluation has
2290 	 * been cancelled due to an aborting error, an interrupt, or an
2291 	 * exception, or we already gave a more specific error.
2292 	 * Also check called_emsg for when using assert_fails().
2293 	 */
2294 	if (!aborting()
2295 		&& did_emsg == did_emsg_before
2296 		&& called_emsg == called_emsg_before
2297 		&& (flags & EVAL_CONSTANT) == 0
2298 		&& (!in_vim9script() || !vim9_bad_comment(p)))
2299 	{
2300 	    if (end_error)
2301 		semsg(_(e_trailing_arg), p);
2302 	    else
2303 		semsg(_(e_invalid_expression_str), arg);
2304 	}
2305 
2306 	// Some of the expression may not have been consumed.  Do not check for
2307 	// a next command to avoid more errors, unless "|" is following, which
2308 	// could only be a command separator.
2309 	if (eap != NULL && skipwhite(p)[0] == '|' && skipwhite(p)[1] != '|')
2310 	    eap->nextcmd = check_nextcmd(p);
2311 	return FAIL;
2312     }
2313 
2314     if (eap != NULL)
2315 	eap->nextcmd = check_nextcmd(p);
2316 
2317     return ret;
2318 }
2319 
2320 /*
2321  * Handle top level expression:
2322  *	expr2 ? expr1 : expr1
2323  *	expr2 ?? expr1
2324  *
2325  * "arg" must point to the first non-white of the expression.
2326  * "arg" is advanced to just after the recognized expression.
2327  *
2328  * Note: "rettv.v_lock" is not set.
2329  *
2330  * Return OK or FAIL.
2331  */
2332     int
2333 eval1(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2334 {
2335     char_u  *p;
2336     int	    getnext;
2337 
2338     CLEAR_POINTER(rettv);
2339 
2340     /*
2341      * Get the first variable.
2342      */
2343     if (eval2(arg, rettv, evalarg) == FAIL)
2344 	return FAIL;
2345 
2346     p = eval_next_non_blank(*arg, evalarg, &getnext);
2347     if (*p == '?')
2348     {
2349 	int		op_falsy = p[1] == '?';
2350 	int		result;
2351 	typval_T	var2;
2352 	evalarg_T	*evalarg_used = evalarg;
2353 	evalarg_T	local_evalarg;
2354 	int		orig_flags;
2355 	int		evaluate;
2356 	int		vim9script = in_vim9script();
2357 
2358 	if (evalarg == NULL)
2359 	{
2360 	    CLEAR_FIELD(local_evalarg);
2361 	    evalarg_used = &local_evalarg;
2362 	}
2363 	orig_flags = evalarg_used->eval_flags;
2364 	evaluate = evalarg_used->eval_flags & EVAL_EVALUATE;
2365 
2366 	if (getnext)
2367 	    *arg = eval_next_line(evalarg_used);
2368 	else
2369 	{
2370 	    if (evaluate && vim9script && !VIM_ISWHITE(p[-1]))
2371 	    {
2372 		error_white_both(p, op_falsy ? 2 : 1);
2373 		clear_tv(rettv);
2374 		return FAIL;
2375 	    }
2376 	    *arg = p;
2377 	}
2378 
2379 	result = FALSE;
2380 	if (evaluate)
2381 	{
2382 	    int		error = FALSE;
2383 
2384 	    if (op_falsy)
2385 		result = tv2bool(rettv);
2386 	    else if (vim9script)
2387 		result = tv_get_bool_chk(rettv, &error);
2388 	    else if (tv_get_number_chk(rettv, &error) != 0)
2389 		result = TRUE;
2390 	    if (error || !op_falsy || !result)
2391 		clear_tv(rettv);
2392 	    if (error)
2393 		return FAIL;
2394 	}
2395 
2396 	/*
2397 	 * Get the second variable.  Recursive!
2398 	 */
2399 	if (op_falsy)
2400 	    ++*arg;
2401 	if (evaluate && vim9script && !IS_WHITE_OR_NUL((*arg)[1]))
2402 	{
2403 	    error_white_both(*arg - (op_falsy ? 1 : 0), op_falsy ? 2 : 1);
2404 	    clear_tv(rettv);
2405 	    return FAIL;
2406 	}
2407 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg_used);
2408 	evalarg_used->eval_flags = (op_falsy ? !result : result)
2409 				    ? orig_flags : orig_flags & ~EVAL_EVALUATE;
2410 	if (eval1(arg, &var2, evalarg_used) == FAIL)
2411 	{
2412 	    evalarg_used->eval_flags = orig_flags;
2413 	    return FAIL;
2414 	}
2415 	if (!op_falsy || !result)
2416 	    *rettv = var2;
2417 
2418 	if (!op_falsy)
2419 	{
2420 	    /*
2421 	     * Check for the ":".
2422 	     */
2423 	    p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2424 	    if (*p != ':')
2425 	    {
2426 		emsg(_(e_missing_colon));
2427 		if (evaluate && result)
2428 		    clear_tv(rettv);
2429 		evalarg_used->eval_flags = orig_flags;
2430 		return FAIL;
2431 	    }
2432 	    if (getnext)
2433 		*arg = eval_next_line(evalarg_used);
2434 	    else
2435 	    {
2436 		if (evaluate && vim9script && !VIM_ISWHITE(p[-1]))
2437 		{
2438 		    error_white_both(p, 1);
2439 		    clear_tv(rettv);
2440 		    evalarg_used->eval_flags = orig_flags;
2441 		    return FAIL;
2442 		}
2443 		*arg = p;
2444 	    }
2445 
2446 	    /*
2447 	     * Get the third variable.  Recursive!
2448 	     */
2449 	    if (evaluate && vim9script && !IS_WHITE_OR_NUL((*arg)[1]))
2450 	    {
2451 		error_white_both(*arg, 1);
2452 		clear_tv(rettv);
2453 		evalarg_used->eval_flags = orig_flags;
2454 		return FAIL;
2455 	    }
2456 	    *arg = skipwhite_and_linebreak(*arg + 1, evalarg_used);
2457 	    evalarg_used->eval_flags = !result ? orig_flags
2458 						 : orig_flags & ~EVAL_EVALUATE;
2459 	    if (eval1(arg, &var2, evalarg_used) == FAIL)
2460 	    {
2461 		if (evaluate && result)
2462 		    clear_tv(rettv);
2463 		evalarg_used->eval_flags = orig_flags;
2464 		return FAIL;
2465 	    }
2466 	    if (evaluate && !result)
2467 		*rettv = var2;
2468 	}
2469 
2470 	if (evalarg == NULL)
2471 	    clear_evalarg(&local_evalarg, NULL);
2472 	else
2473 	    evalarg->eval_flags = orig_flags;
2474     }
2475 
2476     return OK;
2477 }
2478 
2479 /*
2480  * Handle first level expression:
2481  *	expr2 || expr2 || expr2	    logical OR
2482  *
2483  * "arg" must point to the first non-white of the expression.
2484  * "arg" is advanced to just after the recognized expression.
2485  *
2486  * Return OK or FAIL.
2487  */
2488     static int
2489 eval2(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2490 {
2491     char_u	*p;
2492     int		getnext;
2493 
2494     /*
2495      * Get the first variable.
2496      */
2497     if (eval3(arg, rettv, evalarg) == FAIL)
2498 	return FAIL;
2499 
2500     /*
2501      * Handle the  "||" operator.
2502      */
2503     p = eval_next_non_blank(*arg, evalarg, &getnext);
2504     if (p[0] == '|' && p[1] == '|')
2505     {
2506 	evalarg_T   *evalarg_used = evalarg;
2507 	evalarg_T   local_evalarg;
2508 	int	    evaluate;
2509 	int	    orig_flags;
2510 	long	    result = FALSE;
2511 	typval_T    var2;
2512 	int	    error = FALSE;
2513 	int	    vim9script = in_vim9script();
2514 
2515 	if (evalarg == NULL)
2516 	{
2517 	    CLEAR_FIELD(local_evalarg);
2518 	    evalarg_used = &local_evalarg;
2519 	}
2520 	orig_flags = evalarg_used->eval_flags;
2521 	evaluate = orig_flags & EVAL_EVALUATE;
2522 	if (evaluate)
2523 	{
2524 	    if (vim9script)
2525 		result = tv_get_bool_chk(rettv, &error);
2526 	    else if (tv_get_number_chk(rettv, &error) != 0)
2527 		result = TRUE;
2528 	    clear_tv(rettv);
2529 	    if (error)
2530 		return FAIL;
2531 	}
2532 
2533 	/*
2534 	 * Repeat until there is no following "||".
2535 	 */
2536 	while (p[0] == '|' && p[1] == '|')
2537 	{
2538 	    if (getnext)
2539 		*arg = eval_next_line(evalarg_used);
2540 	    else
2541 	    {
2542 		if (evaluate && in_vim9script() && !VIM_ISWHITE(p[-1]))
2543 		{
2544 		    error_white_both(p, 2);
2545 		    clear_tv(rettv);
2546 		    return FAIL;
2547 		}
2548 		*arg = p;
2549 	    }
2550 
2551 	    /*
2552 	     * Get the second variable.
2553 	     */
2554 	    if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[2]))
2555 	    {
2556 		error_white_both(*arg, 2);
2557 		clear_tv(rettv);
2558 		return FAIL;
2559 	    }
2560 	    *arg = skipwhite_and_linebreak(*arg + 2, evalarg_used);
2561 	    evalarg_used->eval_flags = !result ? orig_flags
2562 						 : orig_flags & ~EVAL_EVALUATE;
2563 	    if (eval3(arg, &var2, evalarg_used) == FAIL)
2564 		return FAIL;
2565 
2566 	    /*
2567 	     * Compute the result.
2568 	     */
2569 	    if (evaluate && !result)
2570 	    {
2571 		if (vim9script)
2572 		    result = tv_get_bool_chk(&var2, &error);
2573 		else if (tv_get_number_chk(&var2, &error) != 0)
2574 		    result = TRUE;
2575 		clear_tv(&var2);
2576 		if (error)
2577 		    return FAIL;
2578 	    }
2579 	    if (evaluate)
2580 	    {
2581 		if (vim9script)
2582 		{
2583 		    rettv->v_type = VAR_BOOL;
2584 		    rettv->vval.v_number = result ? VVAL_TRUE : VVAL_FALSE;
2585 		}
2586 		else
2587 		{
2588 		    rettv->v_type = VAR_NUMBER;
2589 		    rettv->vval.v_number = result;
2590 		}
2591 	    }
2592 
2593 	    p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2594 	}
2595 
2596 	if (evalarg == NULL)
2597 	    clear_evalarg(&local_evalarg, NULL);
2598 	else
2599 	    evalarg->eval_flags = orig_flags;
2600     }
2601 
2602     return OK;
2603 }
2604 
2605 /*
2606  * Handle second level expression:
2607  *	expr3 && expr3 && expr3	    logical AND
2608  *
2609  * "arg" must point to the first non-white of the expression.
2610  * "arg" is advanced to just after the recognized expression.
2611  *
2612  * Return OK or FAIL.
2613  */
2614     static int
2615 eval3(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2616 {
2617     char_u	*p;
2618     int		getnext;
2619 
2620     /*
2621      * Get the first variable.
2622      */
2623     if (eval4(arg, rettv, evalarg) == FAIL)
2624 	return FAIL;
2625 
2626     /*
2627      * Handle the "&&" operator.
2628      */
2629     p = eval_next_non_blank(*arg, evalarg, &getnext);
2630     if (p[0] == '&' && p[1] == '&')
2631     {
2632 	evalarg_T   *evalarg_used = evalarg;
2633 	evalarg_T   local_evalarg;
2634 	int	    orig_flags;
2635 	int	    evaluate;
2636 	long	    result = TRUE;
2637 	typval_T    var2;
2638 	int	    error = FALSE;
2639 	int	    vim9script = in_vim9script();
2640 
2641 	if (evalarg == NULL)
2642 	{
2643 	    CLEAR_FIELD(local_evalarg);
2644 	    evalarg_used = &local_evalarg;
2645 	}
2646 	orig_flags = evalarg_used->eval_flags;
2647 	evaluate = orig_flags & EVAL_EVALUATE;
2648 	if (evaluate)
2649 	{
2650 	    if (vim9script)
2651 		result = tv_get_bool_chk(rettv, &error);
2652 	    else if (tv_get_number_chk(rettv, &error) == 0)
2653 		result = FALSE;
2654 	    clear_tv(rettv);
2655 	    if (error)
2656 		return FAIL;
2657 	}
2658 
2659 	/*
2660 	 * Repeat until there is no following "&&".
2661 	 */
2662 	while (p[0] == '&' && p[1] == '&')
2663 	{
2664 	    if (getnext)
2665 		*arg = eval_next_line(evalarg_used);
2666 	    else
2667 	    {
2668 		if (evaluate && vim9script && !VIM_ISWHITE(p[-1]))
2669 		{
2670 		    error_white_both(p, 2);
2671 		    clear_tv(rettv);
2672 		    return FAIL;
2673 		}
2674 		*arg = p;
2675 	    }
2676 
2677 	    /*
2678 	     * Get the second variable.
2679 	     */
2680 	    if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[2]))
2681 	    {
2682 		error_white_both(*arg, 2);
2683 		clear_tv(rettv);
2684 		return FAIL;
2685 	    }
2686 	    *arg = skipwhite_and_linebreak(*arg + 2, evalarg_used);
2687 	    evalarg_used->eval_flags = result ? orig_flags
2688 						 : orig_flags & ~EVAL_EVALUATE;
2689 	    CLEAR_FIELD(var2);
2690 	    if (eval4(arg, &var2, evalarg_used) == FAIL)
2691 		return FAIL;
2692 
2693 	    /*
2694 	     * Compute the result.
2695 	     */
2696 	    if (evaluate && result)
2697 	    {
2698 		if (vim9script)
2699 		    result = tv_get_bool_chk(&var2, &error);
2700 		else if (tv_get_number_chk(&var2, &error) == 0)
2701 		    result = FALSE;
2702 		clear_tv(&var2);
2703 		if (error)
2704 		    return FAIL;
2705 	    }
2706 	    if (evaluate)
2707 	    {
2708 		if (vim9script)
2709 		{
2710 		    rettv->v_type = VAR_BOOL;
2711 		    rettv->vval.v_number = result ? VVAL_TRUE : VVAL_FALSE;
2712 		}
2713 		else
2714 		{
2715 		    rettv->v_type = VAR_NUMBER;
2716 		    rettv->vval.v_number = result;
2717 		}
2718 	    }
2719 
2720 	    p = eval_next_non_blank(*arg, evalarg_used, &getnext);
2721 	}
2722 
2723 	if (evalarg == NULL)
2724 	    clear_evalarg(&local_evalarg, NULL);
2725 	else
2726 	    evalarg->eval_flags = orig_flags;
2727     }
2728 
2729     return OK;
2730 }
2731 
2732 /*
2733  * Handle third level expression:
2734  *	var1 == var2
2735  *	var1 =~ var2
2736  *	var1 != var2
2737  *	var1 !~ var2
2738  *	var1 > var2
2739  *	var1 >= var2
2740  *	var1 < var2
2741  *	var1 <= var2
2742  *	var1 is var2
2743  *	var1 isnot var2
2744  *
2745  * "arg" must point to the first non-white of the expression.
2746  * "arg" is advanced to just after the recognized expression.
2747  *
2748  * Return OK or FAIL.
2749  */
2750     static int
2751 eval4(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2752 {
2753     char_u	*p;
2754     int		getnext;
2755     exprtype_T	type = EXPR_UNKNOWN;
2756     int		len = 2;
2757     int		type_is = FALSE;
2758 
2759     /*
2760      * Get the first variable.
2761      */
2762     if (eval5(arg, rettv, evalarg) == FAIL)
2763 	return FAIL;
2764 
2765     p = eval_next_non_blank(*arg, evalarg, &getnext);
2766     type = get_compare_type(p, &len, &type_is);
2767 
2768     /*
2769      * If there is a comparative operator, use it.
2770      */
2771     if (type != EXPR_UNKNOWN)
2772     {
2773 	typval_T    var2;
2774 	int	    ic;
2775 	int	    vim9script = in_vim9script();
2776 	int	    evaluate = evalarg == NULL
2777 				   ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
2778 
2779 	if (getnext)
2780 	{
2781 	    *arg = eval_next_line(evalarg);
2782 	    p = *arg;
2783 	}
2784 	else if (evaluate && vim9script && !VIM_ISWHITE(**arg))
2785 	{
2786 	    error_white_both(*arg, len);
2787 	    clear_tv(rettv);
2788 	    return FAIL;
2789 	}
2790 
2791 	if (vim9script && type_is && (p[len] == '?' || p[len] == '#'))
2792 	{
2793 	    semsg(_(e_invalid_expression_str), p);
2794 	    clear_tv(rettv);
2795 	    return FAIL;
2796 	}
2797 
2798 	// extra question mark appended: ignore case
2799 	if (p[len] == '?')
2800 	{
2801 	    ic = TRUE;
2802 	    ++len;
2803 	}
2804 	// extra '#' appended: match case
2805 	else if (p[len] == '#')
2806 	{
2807 	    ic = FALSE;
2808 	    ++len;
2809 	}
2810 	// nothing appended: use 'ignorecase' if not in Vim script
2811 	else
2812 	    ic = vim9script ? FALSE : p_ic;
2813 
2814 	/*
2815 	 * Get the second variable.
2816 	 */
2817 	if (evaluate && vim9script && !IS_WHITE_OR_NUL(p[len]))
2818 	{
2819 	    error_white_both(p, len);
2820 	    clear_tv(rettv);
2821 	    return FAIL;
2822 	}
2823 	*arg = skipwhite_and_linebreak(p + len, evalarg);
2824 	if (eval5(arg, &var2, evalarg) == FAIL)
2825 	{
2826 	    clear_tv(rettv);
2827 	    return FAIL;
2828 	}
2829 	if (evaluate)
2830 	{
2831 	    int ret;
2832 
2833 	    if (vim9script && check_compare_types(type, rettv, &var2) == FAIL)
2834 	    {
2835 		ret = FAIL;
2836 		clear_tv(rettv);
2837 	    }
2838 	    else
2839 		ret = typval_compare(rettv, &var2, type, ic);
2840 	    clear_tv(&var2);
2841 	    return ret;
2842 	}
2843     }
2844 
2845     return OK;
2846 }
2847 
2848 /*
2849  * Make a copy of blob "tv1" and append blob "tv2".
2850  */
2851     void
2852 eval_addblob(typval_T *tv1, typval_T *tv2)
2853 {
2854     blob_T  *b1 = tv1->vval.v_blob;
2855     blob_T  *b2 = tv2->vval.v_blob;
2856     blob_T  *b = blob_alloc();
2857     int	    i;
2858 
2859     if (b != NULL)
2860     {
2861 	for (i = 0; i < blob_len(b1); i++)
2862 	    ga_append(&b->bv_ga, blob_get(b1, i));
2863 	for (i = 0; i < blob_len(b2); i++)
2864 	    ga_append(&b->bv_ga, blob_get(b2, i));
2865 
2866 	clear_tv(tv1);
2867 	rettv_blob_set(tv1, b);
2868     }
2869 }
2870 
2871 /*
2872  * Make a copy of list "tv1" and append list "tv2".
2873  */
2874     int
2875 eval_addlist(typval_T *tv1, typval_T *tv2)
2876 {
2877     typval_T var3;
2878 
2879     // concatenate Lists
2880     if (list_concat(tv1->vval.v_list, tv2->vval.v_list, &var3) == FAIL)
2881     {
2882 	clear_tv(tv1);
2883 	clear_tv(tv2);
2884 	return FAIL;
2885     }
2886     clear_tv(tv1);
2887     *tv1 = var3;
2888     return OK;
2889 }
2890 
2891 /*
2892  * Handle fourth level expression:
2893  *	+	number addition
2894  *	-	number subtraction
2895  *	.	string concatenation (if script version is 1)
2896  *	..	string concatenation
2897  *
2898  * "arg" must point to the first non-white of the expression.
2899  * "arg" is advanced to just after the recognized expression.
2900  *
2901  * Return OK or FAIL.
2902  */
2903     static int
2904 eval5(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
2905 {
2906     /*
2907      * Get the first variable.
2908      */
2909     if (eval6(arg, rettv, evalarg, FALSE) == FAIL)
2910 	return FAIL;
2911 
2912     /*
2913      * Repeat computing, until no '+', '-' or '.' is following.
2914      */
2915     for (;;)
2916     {
2917 	int	    evaluate;
2918 	int	    getnext;
2919 	char_u	    *p;
2920 	int	    op;
2921 	int	    oplen;
2922 	int	    concat;
2923 	typval_T    var2;
2924 	int	    vim9script = in_vim9script();
2925 
2926 	// "." is only string concatenation when scriptversion is 1
2927 	// "+=", "-=" and "..=" are assignments
2928 	// "++" and "--" on the next line are a separate command.
2929 	p = eval_next_non_blank(*arg, evalarg, &getnext);
2930 	op = *p;
2931 	concat = op == '.' && (*(p + 1) == '.' || current_sctx.sc_version < 2);
2932 	if ((op != '+' && op != '-' && !concat) || p[1] == '='
2933 					       || (p[1] == '.' && p[2] == '='))
2934 	    break;
2935 	if (getnext && (op == '+' || op == '-') && p[0] == p[1])
2936 	    break;
2937 
2938 	evaluate = evalarg == NULL ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
2939 	oplen = (concat && p[1] == '.') ? 2 : 1;
2940 	if (getnext)
2941 	    *arg = eval_next_line(evalarg);
2942 	else
2943 	{
2944 	    if (evaluate && vim9script && !VIM_ISWHITE(**arg))
2945 	    {
2946 		error_white_both(*arg, oplen);
2947 		clear_tv(rettv);
2948 		return FAIL;
2949 	    }
2950 	    *arg = p;
2951 	}
2952 	if ((op != '+' || (rettv->v_type != VAR_LIST
2953 						 && rettv->v_type != VAR_BLOB))
2954 #ifdef FEAT_FLOAT
2955 		&& (op == '.' || rettv->v_type != VAR_FLOAT)
2956 #endif
2957 		&& evaluate)
2958 	{
2959 	    int		error = FALSE;
2960 
2961 	    // For "list + ...", an illegal use of the first operand as
2962 	    // a number cannot be determined before evaluating the 2nd
2963 	    // operand: if this is also a list, all is ok.
2964 	    // For "something . ...", "something - ..." or "non-list + ...",
2965 	    // we know that the first operand needs to be a string or number
2966 	    // without evaluating the 2nd operand.  So check before to avoid
2967 	    // side effects after an error.
2968 	    if (op != '.')
2969 		tv_get_number_chk(rettv, &error);
2970 	    if ((op == '.' && tv_get_string_chk(rettv) == NULL) || error)
2971 	    {
2972 		clear_tv(rettv);
2973 		return FAIL;
2974 	    }
2975 	}
2976 
2977 	/*
2978 	 * Get the second variable.
2979 	 */
2980 	if (evaluate && vim9script && !IS_WHITE_OR_NUL((*arg)[oplen]))
2981 	{
2982 	    error_white_both(*arg, oplen);
2983 	    clear_tv(rettv);
2984 	    return FAIL;
2985 	}
2986 	*arg = skipwhite_and_linebreak(*arg + oplen, evalarg);
2987 	if (eval6(arg, &var2, evalarg, !vim9script && op == '.') == FAIL)
2988 	{
2989 	    clear_tv(rettv);
2990 	    return FAIL;
2991 	}
2992 
2993 	if (evaluate)
2994 	{
2995 	    /*
2996 	     * Compute the result.
2997 	     */
2998 	    if (op == '.')
2999 	    {
3000 		char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
3001 		char_u	*s1 = tv_get_string_buf(rettv, buf1);
3002 		char_u	*s2 = NULL;
3003 
3004 		if (vim9script && (var2.v_type == VAR_VOID
3005 			|| var2.v_type == VAR_CHANNEL
3006 			|| var2.v_type == VAR_JOB))
3007 		    semsg(_(e_using_invalid_value_as_string_str),
3008 						   vartype_name(var2.v_type));
3009 #ifdef FEAT_FLOAT
3010 		else if (vim9script && var2.v_type == VAR_FLOAT)
3011 		{
3012 		    vim_snprintf((char *)buf2, NUMBUFLEN, "%g",
3013 							    var2.vval.v_float);
3014 		    s2 = buf2;
3015 		}
3016 #endif
3017 		else
3018 		    s2 = tv_get_string_buf_chk(&var2, buf2);
3019 		if (s2 == NULL)		// type error ?
3020 		{
3021 		    clear_tv(rettv);
3022 		    clear_tv(&var2);
3023 		    return FAIL;
3024 		}
3025 		p = concat_str(s1, s2);
3026 		clear_tv(rettv);
3027 		rettv->v_type = VAR_STRING;
3028 		rettv->vval.v_string = p;
3029 	    }
3030 	    else if (op == '+' && rettv->v_type == VAR_BLOB
3031 						   && var2.v_type == VAR_BLOB)
3032 		eval_addblob(rettv, &var2);
3033 	    else if (op == '+' && rettv->v_type == VAR_LIST
3034 						   && var2.v_type == VAR_LIST)
3035 	    {
3036 		if (eval_addlist(rettv, &var2) == FAIL)
3037 		    return FAIL;
3038 	    }
3039 	    else
3040 	    {
3041 		int		error = FALSE;
3042 		varnumber_T	n1, n2;
3043 #ifdef FEAT_FLOAT
3044 		float_T	    f1 = 0, f2 = 0;
3045 
3046 		if (rettv->v_type == VAR_FLOAT)
3047 		{
3048 		    f1 = rettv->vval.v_float;
3049 		    n1 = 0;
3050 		}
3051 		else
3052 #endif
3053 		{
3054 		    n1 = tv_get_number_chk(rettv, &error);
3055 		    if (error)
3056 		    {
3057 			// This can only happen for "list + non-list" or
3058 			// "blob + non-blob".  For "non-list + ..." or
3059 			// "something - ...", we returned before evaluating the
3060 			// 2nd operand.
3061 			clear_tv(rettv);
3062 			clear_tv(&var2);
3063 			return FAIL;
3064 		    }
3065 #ifdef FEAT_FLOAT
3066 		    if (var2.v_type == VAR_FLOAT)
3067 			f1 = n1;
3068 #endif
3069 		}
3070 #ifdef FEAT_FLOAT
3071 		if (var2.v_type == VAR_FLOAT)
3072 		{
3073 		    f2 = var2.vval.v_float;
3074 		    n2 = 0;
3075 		}
3076 		else
3077 #endif
3078 		{
3079 		    n2 = tv_get_number_chk(&var2, &error);
3080 		    if (error)
3081 		    {
3082 			clear_tv(rettv);
3083 			clear_tv(&var2);
3084 			return FAIL;
3085 		    }
3086 #ifdef FEAT_FLOAT
3087 		    if (rettv->v_type == VAR_FLOAT)
3088 			f2 = n2;
3089 #endif
3090 		}
3091 		clear_tv(rettv);
3092 
3093 #ifdef FEAT_FLOAT
3094 		// If there is a float on either side the result is a float.
3095 		if (rettv->v_type == VAR_FLOAT || var2.v_type == VAR_FLOAT)
3096 		{
3097 		    if (op == '+')
3098 			f1 = f1 + f2;
3099 		    else
3100 			f1 = f1 - f2;
3101 		    rettv->v_type = VAR_FLOAT;
3102 		    rettv->vval.v_float = f1;
3103 		}
3104 		else
3105 #endif
3106 		{
3107 		    if (op == '+')
3108 			n1 = n1 + n2;
3109 		    else
3110 			n1 = n1 - n2;
3111 		    rettv->v_type = VAR_NUMBER;
3112 		    rettv->vval.v_number = n1;
3113 		}
3114 	    }
3115 	    clear_tv(&var2);
3116 	}
3117     }
3118     return OK;
3119 }
3120 
3121 /*
3122  * Handle fifth level expression:
3123  *	*	number multiplication
3124  *	/	number division
3125  *	%	number modulo
3126  *
3127  * "arg" must point to the first non-white of the expression.
3128  * "arg" is advanced to just after the recognized expression.
3129  *
3130  * Return OK or FAIL.
3131  */
3132     static int
3133 eval6(
3134     char_u	**arg,
3135     typval_T	*rettv,
3136     evalarg_T	*evalarg,
3137     int		want_string)  // after "." operator
3138 {
3139 #ifdef FEAT_FLOAT
3140     int	    use_float = FALSE;
3141 #endif
3142 
3143     /*
3144      * Get the first variable.
3145      */
3146     if (eval7t(arg, rettv, evalarg, want_string) == FAIL)
3147 	return FAIL;
3148 
3149     /*
3150      * Repeat computing, until no '*', '/' or '%' is following.
3151      */
3152     for (;;)
3153     {
3154 	int	    evaluate;
3155 	int	    getnext;
3156 	typval_T    var2;
3157 	char_u	    *p;
3158 	int	    op;
3159 	varnumber_T n1, n2;
3160 #ifdef FEAT_FLOAT
3161 	float_T	    f1, f2;
3162 #endif
3163 	int	    error;
3164 
3165 	// "*=", "/=" and "%=" are assignments
3166 	p = eval_next_non_blank(*arg, evalarg, &getnext);
3167 	op = *p;
3168 	if ((op != '*' && op != '/' && op != '%') || p[1] == '=')
3169 	    break;
3170 
3171 	evaluate = evalarg == NULL ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
3172 	if (getnext)
3173 	    *arg = eval_next_line(evalarg);
3174 	else
3175 	{
3176 	    if (evaluate && in_vim9script() && !VIM_ISWHITE(**arg))
3177 	    {
3178 		error_white_both(*arg, 1);
3179 		clear_tv(rettv);
3180 		return FAIL;
3181 	    }
3182 	    *arg = p;
3183 	}
3184 
3185 #ifdef FEAT_FLOAT
3186 	f1 = 0;
3187 	f2 = 0;
3188 #endif
3189 	error = FALSE;
3190 	if (evaluate)
3191 	{
3192 #ifdef FEAT_FLOAT
3193 	    if (rettv->v_type == VAR_FLOAT)
3194 	    {
3195 		f1 = rettv->vval.v_float;
3196 		use_float = TRUE;
3197 		n1 = 0;
3198 	    }
3199 	    else
3200 #endif
3201 		n1 = tv_get_number_chk(rettv, &error);
3202 	    clear_tv(rettv);
3203 	    if (error)
3204 		return FAIL;
3205 	}
3206 	else
3207 	    n1 = 0;
3208 
3209 	/*
3210 	 * Get the second variable.
3211 	 */
3212 	if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[1]))
3213 	{
3214 	    error_white_both(*arg, 1);
3215 	    clear_tv(rettv);
3216 	    return FAIL;
3217 	}
3218 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3219 	if (eval7t(arg, &var2, evalarg, FALSE) == FAIL)
3220 	    return FAIL;
3221 
3222 	if (evaluate)
3223 	{
3224 #ifdef FEAT_FLOAT
3225 	    if (var2.v_type == VAR_FLOAT)
3226 	    {
3227 		if (!use_float)
3228 		{
3229 		    f1 = n1;
3230 		    use_float = TRUE;
3231 		}
3232 		f2 = var2.vval.v_float;
3233 		n2 = 0;
3234 	    }
3235 	    else
3236 #endif
3237 	    {
3238 		n2 = tv_get_number_chk(&var2, &error);
3239 		clear_tv(&var2);
3240 		if (error)
3241 		    return FAIL;
3242 #ifdef FEAT_FLOAT
3243 		if (use_float)
3244 		    f2 = n2;
3245 #endif
3246 	    }
3247 
3248 	    /*
3249 	     * Compute the result.
3250 	     * When either side is a float the result is a float.
3251 	     */
3252 #ifdef FEAT_FLOAT
3253 	    if (use_float)
3254 	    {
3255 		if (op == '*')
3256 		    f1 = f1 * f2;
3257 		else if (op == '/')
3258 		{
3259 # ifdef VMS
3260 		    // VMS crashes on divide by zero, work around it
3261 		    if (f2 == 0.0)
3262 		    {
3263 			if (f1 == 0)
3264 			    f1 = -1 * __F_FLT_MAX - 1L;   // similar to NaN
3265 			else if (f1 < 0)
3266 			    f1 = -1 * __F_FLT_MAX;
3267 			else
3268 			    f1 = __F_FLT_MAX;
3269 		    }
3270 		    else
3271 			f1 = f1 / f2;
3272 # else
3273 		    // We rely on the floating point library to handle divide
3274 		    // by zero to result in "inf" and not a crash.
3275 		    f1 = f1 / f2;
3276 # endif
3277 		}
3278 		else
3279 		{
3280 		    emsg(_(e_modulus));
3281 		    return FAIL;
3282 		}
3283 		rettv->v_type = VAR_FLOAT;
3284 		rettv->vval.v_float = f1;
3285 	    }
3286 	    else
3287 #endif
3288 	    {
3289 		int	    failed = FALSE;
3290 
3291 		if (op == '*')
3292 		    n1 = n1 * n2;
3293 		else if (op == '/')
3294 		    n1 = num_divide(n1, n2, &failed);
3295 		else
3296 		    n1 = num_modulus(n1, n2, &failed);
3297 		if (failed)
3298 		    return FAIL;
3299 
3300 		rettv->v_type = VAR_NUMBER;
3301 		rettv->vval.v_number = n1;
3302 	    }
3303 	}
3304     }
3305 
3306     return OK;
3307 }
3308 
3309 /*
3310  * Handle a type cast before a base level expression.
3311  * "arg" must point to the first non-white of the expression.
3312  * "arg" is advanced to just after the recognized expression.
3313  * Return OK or FAIL.
3314  */
3315     static int
3316 eval7t(
3317     char_u	**arg,
3318     typval_T	*rettv,
3319     evalarg_T	*evalarg,
3320     int		want_string)	// after "." operator
3321 {
3322     type_T	*want_type = NULL;
3323     garray_T	type_list;	    // list of pointers to allocated types
3324     int		res;
3325     int		evaluate = evalarg == NULL ? 0
3326 				       : (evalarg->eval_flags & EVAL_EVALUATE);
3327 
3328     // Recognize <type> in Vim9 script only.
3329     if (in_vim9script() && **arg == '<' && eval_isnamec1((*arg)[1])
3330 					     && STRNCMP(*arg, "<SNR>", 5) != 0)
3331     {
3332 	++*arg;
3333 	ga_init2(&type_list, sizeof(type_T *), 10);
3334 	want_type = parse_type(arg, &type_list, TRUE);
3335 	if (want_type == NULL && (evaluate || **arg != '>'))
3336 	{
3337 	    clear_type_list(&type_list);
3338 	    return FAIL;
3339 	}
3340 
3341 	if (**arg != '>')
3342 	{
3343 	    if (*skipwhite(*arg) == '>')
3344 		semsg(_(e_no_white_space_allowed_before_str_str), ">", *arg);
3345 	    else
3346 		emsg(_(e_missing_gt));
3347 	    clear_type_list(&type_list);
3348 	    return FAIL;
3349 	}
3350 	++*arg;
3351 	*arg = skipwhite_and_linebreak(*arg, evalarg);
3352     }
3353 
3354     res = eval7(arg, rettv, evalarg, want_string);
3355 
3356     if (want_type != NULL && evaluate)
3357     {
3358 	if (res == OK)
3359 	{
3360 	    type_T *actual = typval2type(rettv, get_copyID(), &type_list, TRUE);
3361 
3362 	    if (!equal_type(want_type, actual))
3363 	    {
3364 		if (want_type == &t_bool && actual != &t_bool
3365 					&& (actual->tt_flags & TTFLAG_BOOL_OK))
3366 		{
3367 		    int n = tv2bool(rettv);
3368 
3369 		    // can use "0" and "1" for boolean in some places
3370 		    clear_tv(rettv);
3371 		    rettv->v_type = VAR_BOOL;
3372 		    rettv->vval.v_number = n ? VVAL_TRUE : VVAL_FALSE;
3373 		}
3374 		else
3375 		{
3376 		    where_T where = WHERE_INIT;
3377 
3378 		    where.wt_variable = TRUE;
3379 		    res = check_type(want_type, actual, TRUE, where);
3380 		}
3381 	    }
3382 	}
3383 	clear_type_list(&type_list);
3384     }
3385 
3386     return res;
3387 }
3388 
3389     int
3390 eval_leader(char_u **arg, int vim9)
3391 {
3392     char_u	*s = *arg;
3393     char_u	*p = *arg;
3394 
3395     while (*p == '!' || *p == '-' || *p == '+')
3396     {
3397 	char_u *n = skipwhite(p + 1);
3398 
3399 	// ++, --, -+ and +- are not accepted in Vim9 script
3400 	if (vim9 && (*p == '-' || *p == '+') && (*n == '-' || *n == '+'))
3401 	{
3402 	    semsg(_(e_invalid_expression_str), s);
3403 	    return FAIL;
3404 	}
3405 	p = n;
3406     }
3407     *arg = p;
3408     return OK;
3409 }
3410 
3411 /*
3412  * Handle sixth level expression:
3413  *  number		number constant
3414  *  0zFFFFFFFF		Blob constant
3415  *  "string"		string constant
3416  *  'string'		literal string constant
3417  *  &option-name	option value
3418  *  @r			register contents
3419  *  identifier		variable value
3420  *  function()		function call
3421  *  $VAR		environment variable
3422  *  (expression)	nested expression
3423  *  [expr, expr]	List
3424  *  {arg, arg -> expr}	Lambda
3425  *  {key: val, key: val}   Dictionary
3426  *  #{key: val, key: val}  Dictionary with literal keys
3427  *
3428  *  Also handle:
3429  *  ! in front		logical NOT
3430  *  - in front		unary minus
3431  *  + in front		unary plus (ignored)
3432  *  trailing []		subscript in String or List
3433  *  trailing .name	entry in Dictionary
3434  *  trailing ->name()	method call
3435  *
3436  * "arg" must point to the first non-white of the expression.
3437  * "arg" is advanced to just after the recognized expression.
3438  *
3439  * Return OK or FAIL.
3440  */
3441     static int
3442 eval7(
3443     char_u	**arg,
3444     typval_T	*rettv,
3445     evalarg_T	*evalarg,
3446     int		want_string)	// after "." operator
3447 {
3448     int		evaluate = evalarg != NULL
3449 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3450     int		len;
3451     char_u	*s;
3452     char_u	*start_leader, *end_leader;
3453     int		ret = OK;
3454     char_u	*alias;
3455 
3456     /*
3457      * Initialise variable so that clear_tv() can't mistake this for a
3458      * string and free a string that isn't there.
3459      */
3460     rettv->v_type = VAR_UNKNOWN;
3461 
3462     /*
3463      * Skip '!', '-' and '+' characters.  They are handled later.
3464      */
3465     start_leader = *arg;
3466     if (eval_leader(arg, in_vim9script()) == FAIL)
3467 	return FAIL;
3468     end_leader = *arg;
3469 
3470     if (**arg == '.' && (!isdigit(*(*arg + 1))
3471 #ifdef FEAT_FLOAT
3472 	    || current_sctx.sc_version < 2
3473 #endif
3474 	    ))
3475     {
3476 	semsg(_(e_invalid_expression_str), *arg);
3477 	++*arg;
3478 	return FAIL;
3479     }
3480 
3481     switch (**arg)
3482     {
3483     /*
3484      * Number constant.
3485      */
3486     case '0':
3487     case '1':
3488     case '2':
3489     case '3':
3490     case '4':
3491     case '5':
3492     case '6':
3493     case '7':
3494     case '8':
3495     case '9':
3496     case '.':	ret = eval_number(arg, rettv, evaluate, want_string);
3497 
3498 		// Apply prefixed "-" and "+" now.  Matters especially when
3499 		// "->" follows.
3500 		if (ret == OK && evaluate && end_leader > start_leader
3501 						  && rettv->v_type != VAR_BLOB)
3502 		    ret = eval7_leader(rettv, TRUE, start_leader, &end_leader);
3503 		break;
3504 
3505     /*
3506      * String constant: "string".
3507      */
3508     case '"':	ret = eval_string(arg, rettv, evaluate);
3509 		break;
3510 
3511     /*
3512      * Literal string constant: 'str''ing'.
3513      */
3514     case '\'':	ret = eval_lit_string(arg, rettv, evaluate);
3515 		break;
3516 
3517     /*
3518      * List: [expr, expr]
3519      */
3520     case '[':	ret = eval_list(arg, rettv, evalarg, TRUE);
3521 		break;
3522 
3523     /*
3524      * Dictionary: #{key: val, key: val}
3525      */
3526     case '#':	if (in_vim9script())
3527 		{
3528 		    ret = vim9_bad_comment(*arg) ? FAIL : NOTDONE;
3529 		}
3530 		else if ((*arg)[1] == '{')
3531 		{
3532 		    ++*arg;
3533 		    ret = eval_dict(arg, rettv, evalarg, TRUE);
3534 		}
3535 		else
3536 		    ret = NOTDONE;
3537 		break;
3538 
3539     /*
3540      * Lambda: {arg, arg -> expr}
3541      * Dictionary: {'key': val, 'key': val}
3542      */
3543     case '{':	if (in_vim9script())
3544 		    ret = NOTDONE;
3545 		else
3546 		    ret = get_lambda_tv(arg, rettv, in_vim9script(), evalarg);
3547 		if (ret == NOTDONE)
3548 		    ret = eval_dict(arg, rettv, evalarg, FALSE);
3549 		break;
3550 
3551     /*
3552      * Option value: &name
3553      */
3554     case '&':	ret = eval_option(arg, rettv, evaluate);
3555 		break;
3556 
3557     /*
3558      * Environment variable: $VAR.
3559      */
3560     case '$':	ret = eval_env_var(arg, rettv, evaluate);
3561 		break;
3562 
3563     /*
3564      * Register contents: @r.
3565      */
3566     case '@':	++*arg;
3567 		if (evaluate)
3568 		{
3569 		    if (in_vim9script() && IS_WHITE_OR_NUL(**arg))
3570 			semsg(_(e_syntax_error_at_str), *arg);
3571 		    else if (in_vim9script() && !valid_yank_reg(**arg, FALSE))
3572 			emsg_invreg(**arg);
3573 		    else
3574 		    {
3575 			rettv->v_type = VAR_STRING;
3576 			rettv->vval.v_string = get_reg_contents(**arg,
3577 								GREG_EXPR_SRC);
3578 		    }
3579 		}
3580 		if (**arg != NUL)
3581 		    ++*arg;
3582 		break;
3583 
3584     /*
3585      * nested expression: (expression).
3586      * or lambda: (arg) => expr
3587      */
3588     case '(':	ret = NOTDONE;
3589 		if (in_vim9script())
3590 		{
3591 		    ret = get_lambda_tv(arg, rettv, TRUE, evalarg);
3592 		    if (ret == OK && evaluate)
3593 		    {
3594 			ufunc_T *ufunc = rettv->vval.v_partial->pt_func;
3595 
3596 			// Compile it here to get the return type.  The return
3597 			// type is optional, when it's missing use t_unknown.
3598 			// This is recognized in compile_return().
3599 			if (ufunc->uf_ret_type->tt_type == VAR_VOID)
3600 			    ufunc->uf_ret_type = &t_unknown;
3601 			if (compile_def_function(ufunc,
3602 				     FALSE, COMPILE_TYPE(ufunc), NULL) == FAIL)
3603 			{
3604 			    clear_tv(rettv);
3605 			    ret = FAIL;
3606 			}
3607 		    }
3608 		}
3609 		if (ret == NOTDONE)
3610 		{
3611 		    *arg = skipwhite_and_linebreak(*arg + 1, evalarg);
3612 		    ret = eval1(arg, rettv, evalarg);	// recursive!
3613 
3614 		    *arg = skipwhite_and_linebreak(*arg, evalarg);
3615 		    if (**arg == ')')
3616 			++*arg;
3617 		    else if (ret == OK)
3618 		    {
3619 			emsg(_(e_missing_close));
3620 			clear_tv(rettv);
3621 			ret = FAIL;
3622 		    }
3623 		}
3624 		break;
3625 
3626     default:	ret = NOTDONE;
3627 		break;
3628     }
3629 
3630     if (ret == NOTDONE)
3631     {
3632 	/*
3633 	 * Must be a variable or function name.
3634 	 * Can also be a curly-braces kind of name: {expr}.
3635 	 */
3636 	s = *arg;
3637 	len = get_name_len(arg, &alias, evaluate, TRUE);
3638 	if (alias != NULL)
3639 	    s = alias;
3640 
3641 	if (len <= 0)
3642 	    ret = FAIL;
3643 	else
3644 	{
3645 	    int	    flags = evalarg == NULL ? 0 : evalarg->eval_flags;
3646 
3647 	    if (evaluate && in_vim9script() && len == 1 && *s == '_')
3648 	    {
3649 		emsg(_(e_cannot_use_underscore_here));
3650 		ret = FAIL;
3651 	    }
3652 	    else if ((in_vim9script() ? **arg : *skipwhite(*arg)) == '(')
3653 	    {
3654 		// "name(..."  recursive!
3655 		*arg = skipwhite(*arg);
3656 		ret = eval_func(arg, evalarg, s, len, rettv, flags, NULL);
3657 	    }
3658 	    else if (flags & EVAL_CONSTANT)
3659 		ret = FAIL;
3660 	    else if (evaluate)
3661 	    {
3662 		// get the value of "true", "false" or a variable
3663 		if (len == 4 && in_vim9script() && STRNCMP(s, "true", 4) == 0)
3664 		{
3665 		    rettv->v_type = VAR_BOOL;
3666 		    rettv->vval.v_number = VVAL_TRUE;
3667 		    ret = OK;
3668 		}
3669 		else if (len == 5 && in_vim9script()
3670 						&& STRNCMP(s, "false", 5) == 0)
3671 		{
3672 		    rettv->v_type = VAR_BOOL;
3673 		    rettv->vval.v_number = VVAL_FALSE;
3674 		    ret = OK;
3675 		}
3676 		else if (len == 4 && in_vim9script()
3677 						&& STRNCMP(s, "null", 4) == 0)
3678 		{
3679 		    rettv->v_type = VAR_SPECIAL;
3680 		    rettv->vval.v_number = VVAL_NULL;
3681 		    ret = OK;
3682 		}
3683 		else
3684 		    ret = eval_variable(s, len, rettv, NULL,
3685 					   EVAL_VAR_VERBOSE + EVAL_VAR_IMPORT);
3686 	    }
3687 	    else
3688 	    {
3689 		// skip the name
3690 		check_vars(s, len);
3691 		ret = OK;
3692 	    }
3693 	}
3694 	vim_free(alias);
3695     }
3696 
3697     // Handle following '[', '(' and '.' for expr[expr], expr.name,
3698     // expr(expr), expr->name(expr)
3699     if (ret == OK)
3700 	ret = handle_subscript(arg, rettv, evalarg, TRUE);
3701 
3702     /*
3703      * Apply logical NOT and unary '-', from right to left, ignore '+'.
3704      */
3705     if (ret == OK && evaluate && end_leader > start_leader)
3706 	ret = eval7_leader(rettv, FALSE, start_leader, &end_leader);
3707     return ret;
3708 }
3709 
3710 /*
3711  * Apply the leading "!" and "-" before an eval7 expression to "rettv".
3712  * When "numeric_only" is TRUE only handle "+" and "-".
3713  * Adjusts "end_leaderp" until it is at "start_leader".
3714  */
3715     static int
3716 eval7_leader(
3717 	typval_T    *rettv,
3718 	int	    numeric_only,
3719 	char_u	    *start_leader,
3720 	char_u	    **end_leaderp)
3721 {
3722     char_u	*end_leader = *end_leaderp;
3723     int		ret = OK;
3724     int		error = FALSE;
3725     varnumber_T val = 0;
3726     vartype_T	type = rettv->v_type;
3727 #ifdef FEAT_FLOAT
3728     float_T	    f = 0.0;
3729 
3730     if (rettv->v_type == VAR_FLOAT)
3731 	f = rettv->vval.v_float;
3732     else
3733 #endif
3734     {
3735 	while (VIM_ISWHITE(end_leader[-1]))
3736 	    --end_leader;
3737 	if (in_vim9script() && end_leader[-1] == '!')
3738 	    val = tv2bool(rettv);
3739 	else
3740 	    val = tv_get_number_chk(rettv, &error);
3741     }
3742     if (error)
3743     {
3744 	clear_tv(rettv);
3745 	ret = FAIL;
3746     }
3747     else
3748     {
3749 	while (end_leader > start_leader)
3750 	{
3751 	    --end_leader;
3752 	    if (*end_leader == '!')
3753 	    {
3754 		if (numeric_only)
3755 		{
3756 		    ++end_leader;
3757 		    break;
3758 		}
3759 #ifdef FEAT_FLOAT
3760 		if (rettv->v_type == VAR_FLOAT)
3761 		{
3762 		    if (in_vim9script())
3763 		    {
3764 			rettv->v_type = VAR_BOOL;
3765 			val = f == 0.0 ? VVAL_TRUE : VVAL_FALSE;
3766 		    }
3767 		    else
3768 			f = !f;
3769 		}
3770 		else
3771 #endif
3772 		{
3773 		    val = !val;
3774 		    type = VAR_BOOL;
3775 		}
3776 	    }
3777 	    else if (*end_leader == '-')
3778 	    {
3779 #ifdef FEAT_FLOAT
3780 		if (rettv->v_type == VAR_FLOAT)
3781 		    f = -f;
3782 		else
3783 #endif
3784 		{
3785 		    val = -val;
3786 		    type = VAR_NUMBER;
3787 		}
3788 	    }
3789 	}
3790 #ifdef FEAT_FLOAT
3791 	if (rettv->v_type == VAR_FLOAT)
3792 	{
3793 	    clear_tv(rettv);
3794 	    rettv->vval.v_float = f;
3795 	}
3796 	else
3797 #endif
3798 	{
3799 	    clear_tv(rettv);
3800 	    if (in_vim9script())
3801 		rettv->v_type = type;
3802 	    else
3803 		rettv->v_type = VAR_NUMBER;
3804 	    rettv->vval.v_number = val;
3805 	}
3806     }
3807     *end_leaderp = end_leader;
3808     return ret;
3809 }
3810 
3811 /*
3812  * Call the function referred to in "rettv".
3813  */
3814     static int
3815 call_func_rettv(
3816 	char_u	    **arg,
3817 	evalarg_T   *evalarg,
3818 	typval_T    *rettv,
3819 	int	    evaluate,
3820 	dict_T	    *selfdict,
3821 	typval_T    *basetv)
3822 {
3823     partial_T	*pt = NULL;
3824     funcexe_T	funcexe;
3825     typval_T	functv;
3826     char_u	*s;
3827     int		ret;
3828 
3829     // need to copy the funcref so that we can clear rettv
3830     if (evaluate)
3831     {
3832 	functv = *rettv;
3833 	rettv->v_type = VAR_UNKNOWN;
3834 
3835 	// Invoke the function.  Recursive!
3836 	if (functv.v_type == VAR_PARTIAL)
3837 	{
3838 	    pt = functv.vval.v_partial;
3839 	    s = partial_name(pt);
3840 	}
3841 	else
3842 	{
3843 	    s = functv.vval.v_string;
3844 	    if (s == NULL || *s == NUL)
3845 	    {
3846 		emsg(_(e_empty_function_name));
3847 		ret = FAIL;
3848 		goto theend;
3849 	    }
3850 	}
3851     }
3852     else
3853 	s = (char_u *)"";
3854 
3855     CLEAR_FIELD(funcexe);
3856     funcexe.firstline = curwin->w_cursor.lnum;
3857     funcexe.lastline = curwin->w_cursor.lnum;
3858     funcexe.evaluate = evaluate;
3859     funcexe.partial = pt;
3860     funcexe.selfdict = selfdict;
3861     funcexe.basetv = basetv;
3862     ret = get_func_tv(s, -1, rettv, arg, evalarg, &funcexe);
3863 
3864 theend:
3865     // Clear the funcref afterwards, so that deleting it while
3866     // evaluating the arguments is possible (see test55).
3867     if (evaluate)
3868 	clear_tv(&functv);
3869 
3870     return ret;
3871 }
3872 
3873 /*
3874  * Evaluate "->method()".
3875  * "*arg" points to "method".
3876  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
3877  */
3878     static int
3879 eval_lambda(
3880     char_u	**arg,
3881     typval_T	*rettv,
3882     evalarg_T	*evalarg,
3883     int		verbose)	// give error messages
3884 {
3885     int		evaluate = evalarg != NULL
3886 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3887     typval_T	base = *rettv;
3888     int		ret;
3889 
3890     rettv->v_type = VAR_UNKNOWN;
3891 
3892     if (**arg == '{')
3893     {
3894 	// ->{lambda}()
3895 	ret = get_lambda_tv(arg, rettv, FALSE, evalarg);
3896     }
3897     else
3898     {
3899 	// ->(lambda)()
3900 	++*arg;
3901 	ret = eval1(arg, rettv, evalarg);
3902 	*arg = skipwhite_and_linebreak(*arg, evalarg);
3903 	if (**arg != ')')
3904 	{
3905 	    emsg(_(e_missing_close));
3906 	    ret = FAIL;
3907 	}
3908 	++*arg;
3909     }
3910     if (ret != OK)
3911 	return FAIL;
3912     else if (**arg != '(')
3913     {
3914 	if (verbose)
3915 	{
3916 	    if (*skipwhite(*arg) == '(')
3917 		emsg(_(e_nowhitespace));
3918 	    else
3919 		semsg(_(e_missing_paren), "lambda");
3920 	}
3921 	clear_tv(rettv);
3922 	ret = FAIL;
3923     }
3924     else
3925 	ret = call_func_rettv(arg, evalarg, rettv, evaluate, NULL, &base);
3926 
3927     // Clear the funcref afterwards, so that deleting it while
3928     // evaluating the arguments is possible (see test55).
3929     if (evaluate)
3930 	clear_tv(&base);
3931 
3932     return ret;
3933 }
3934 
3935 /*
3936  * Evaluate "->method()".
3937  * "*arg" points to "method".
3938  * Returns FAIL or OK. "*arg" is advanced to after the ')'.
3939  */
3940     static int
3941 eval_method(
3942     char_u	**arg,
3943     typval_T	*rettv,
3944     evalarg_T	*evalarg,
3945     int		verbose)	// give error messages
3946 {
3947     char_u	*name;
3948     long	len;
3949     char_u	*alias;
3950     typval_T	base = *rettv;
3951     int		ret;
3952     int		evaluate = evalarg != NULL
3953 				      && (evalarg->eval_flags & EVAL_EVALUATE);
3954 
3955     rettv->v_type = VAR_UNKNOWN;
3956 
3957     name = *arg;
3958     len = get_name_len(arg, &alias, evaluate, TRUE);
3959     if (alias != NULL)
3960 	name = alias;
3961 
3962     if (len <= 0)
3963     {
3964 	if (verbose)
3965 	    emsg(_("E260: Missing name after ->"));
3966 	ret = FAIL;
3967     }
3968     else
3969     {
3970 	*arg = skipwhite(*arg);
3971 	if (**arg != '(')
3972 	{
3973 	    if (verbose)
3974 		semsg(_(e_missing_paren), name);
3975 	    ret = FAIL;
3976 	}
3977 	else if (VIM_ISWHITE((*arg)[-1]))
3978 	{
3979 	    if (verbose)
3980 		emsg(_(e_nowhitespace));
3981 	    ret = FAIL;
3982 	}
3983 	else
3984 	    ret = eval_func(arg, evalarg, name, len, rettv,
3985 					  evaluate ? EVAL_EVALUATE : 0, &base);
3986     }
3987 
3988     // Clear the funcref afterwards, so that deleting it while
3989     // evaluating the arguments is possible (see test55).
3990     if (evaluate)
3991 	clear_tv(&base);
3992 
3993     return ret;
3994 }
3995 
3996 /*
3997  * Evaluate an "[expr]" or "[expr:expr]" index.  Also "dict.key".
3998  * "*arg" points to the '[' or '.'.
3999  * Returns FAIL or OK. "*arg" is advanced to after the ']'.
4000  */
4001     static int
4002 eval_index(
4003     char_u	**arg,
4004     typval_T	*rettv,
4005     evalarg_T	*evalarg,
4006     int		verbose)	// give error messages
4007 {
4008     int		evaluate = evalarg != NULL
4009 				      && (evalarg->eval_flags & EVAL_EVALUATE);
4010     int		empty1 = FALSE, empty2 = FALSE;
4011     typval_T	var1, var2;
4012     int		range = FALSE;
4013     char_u	*key = NULL;
4014     int		keylen = -1;
4015     int		vim9 = in_vim9script();
4016 
4017     if (check_can_index(rettv, evaluate, verbose) == FAIL)
4018 	return FAIL;
4019 
4020     init_tv(&var1);
4021     init_tv(&var2);
4022     if (**arg == '.')
4023     {
4024 	/*
4025 	 * dict.name
4026 	 */
4027 	key = *arg + 1;
4028 	for (keylen = 0; eval_isdictc(key[keylen]); ++keylen)
4029 	    ;
4030 	if (keylen == 0)
4031 	    return FAIL;
4032 	*arg = key + keylen;
4033     }
4034     else
4035     {
4036 	/*
4037 	 * something[idx]
4038 	 *
4039 	 * Get the (first) variable from inside the [].
4040 	 */
4041 	*arg = skipwhite_and_linebreak(*arg + 1, evalarg);
4042 	if (**arg == ':')
4043 	    empty1 = TRUE;
4044 	else if (eval1(arg, &var1, evalarg) == FAIL)	// recursive!
4045 	    return FAIL;
4046 	else if (vim9 && **arg == ':')
4047 	{
4048 	    semsg(_(e_white_space_required_before_and_after_str_at_str),
4049 								    ":", *arg);
4050 	    clear_tv(&var1);
4051 	    return FAIL;
4052 	}
4053 	else if (evaluate)
4054 	{
4055 #ifdef FEAT_FLOAT
4056 	    // allow for indexing with float
4057 	    if (vim9 && rettv->v_type == VAR_DICT
4058 						   && var1.v_type == VAR_FLOAT)
4059 	    {
4060 		var1.vval.v_string = typval_tostring(&var1, TRUE);
4061 		var1.v_type = VAR_STRING;
4062 	    }
4063 #endif
4064 	    if (tv_get_string_chk(&var1) == NULL)
4065 	    {
4066 		// not a number or string
4067 		clear_tv(&var1);
4068 		return FAIL;
4069 	    }
4070 	}
4071 
4072 	/*
4073 	 * Get the second variable from inside the [:].
4074 	 */
4075 	*arg = skipwhite_and_linebreak(*arg, evalarg);
4076 	if (**arg == ':')
4077 	{
4078 	    range = TRUE;
4079 	    ++*arg;
4080 	    if (vim9 && !IS_WHITE_OR_NUL(**arg) && **arg != ']')
4081 	    {
4082 		semsg(_(e_white_space_required_before_and_after_str_at_str),
4083 								":", *arg - 1);
4084 		if (!empty1)
4085 		    clear_tv(&var1);
4086 		return FAIL;
4087 	    }
4088 	    *arg = skipwhite_and_linebreak(*arg, evalarg);
4089 	    if (**arg == ']')
4090 		empty2 = TRUE;
4091 	    else if (eval1(arg, &var2, evalarg) == FAIL)	// recursive!
4092 	    {
4093 		if (!empty1)
4094 		    clear_tv(&var1);
4095 		return FAIL;
4096 	    }
4097 	    else if (evaluate && tv_get_string_chk(&var2) == NULL)
4098 	    {
4099 		// not a number or string
4100 		if (!empty1)
4101 		    clear_tv(&var1);
4102 		clear_tv(&var2);
4103 		return FAIL;
4104 	    }
4105 	}
4106 
4107 	// Check for the ']'.
4108 	*arg = skipwhite_and_linebreak(*arg, evalarg);
4109 	if (**arg != ']')
4110 	{
4111 	    if (verbose)
4112 		emsg(_(e_missbrac));
4113 	    clear_tv(&var1);
4114 	    if (range)
4115 		clear_tv(&var2);
4116 	    return FAIL;
4117 	}
4118 	*arg = *arg + 1;	// skip over the ']'
4119     }
4120 
4121     if (evaluate)
4122     {
4123 	int res = eval_index_inner(rettv, range,
4124 		empty1 ? NULL : &var1, empty2 ? NULL : &var2, FALSE,
4125 		key, keylen, verbose);
4126 
4127 	if (!empty1)
4128 	    clear_tv(&var1);
4129 	if (range)
4130 	    clear_tv(&var2);
4131 	return res;
4132     }
4133     return OK;
4134 }
4135 
4136 /*
4137  * Check if "rettv" can have an [index] or [sli:ce]
4138  */
4139     int
4140 check_can_index(typval_T *rettv, int evaluate, int verbose)
4141 {
4142     switch (rettv->v_type)
4143     {
4144 	case VAR_FUNC:
4145 	case VAR_PARTIAL:
4146 	    if (verbose)
4147 		emsg(_("E695: Cannot index a Funcref"));
4148 	    return FAIL;
4149 	case VAR_FLOAT:
4150 #ifdef FEAT_FLOAT
4151 	    if (verbose)
4152 		emsg(_(e_float_as_string));
4153 	    return FAIL;
4154 #endif
4155 	case VAR_BOOL:
4156 	case VAR_SPECIAL:
4157 	case VAR_JOB:
4158 	case VAR_CHANNEL:
4159 	case VAR_INSTR:
4160 	    if (verbose)
4161 		emsg(_(e_cannot_index_special_variable));
4162 	    return FAIL;
4163 	case VAR_UNKNOWN:
4164 	case VAR_ANY:
4165 	case VAR_VOID:
4166 	    if (evaluate)
4167 	    {
4168 		emsg(_(e_cannot_index_special_variable));
4169 		return FAIL;
4170 	    }
4171 	    // FALLTHROUGH
4172 
4173 	case VAR_STRING:
4174 	case VAR_LIST:
4175 	case VAR_DICT:
4176 	case VAR_BLOB:
4177 	    break;
4178 	case VAR_NUMBER:
4179 	    if (in_vim9script())
4180 		emsg(_(e_cannot_index_number));
4181 	    break;
4182     }
4183     return OK;
4184 }
4185 
4186 /*
4187  * slice() function
4188  */
4189     void
4190 f_slice(typval_T *argvars, typval_T *rettv)
4191 {
4192     if (in_vim9script()
4193 	    && ((argvars[0].v_type != VAR_STRING
4194 		    && argvars[0].v_type != VAR_LIST
4195 		    && argvars[0].v_type != VAR_BLOB
4196 		    && check_for_list_arg(argvars, 0) == FAIL)
4197 		|| check_for_number_arg(argvars, 1) == FAIL
4198 		|| check_for_opt_number_arg(argvars, 2) == FAIL))
4199 	return;
4200 
4201     if (check_can_index(argvars, TRUE, FALSE) == OK)
4202     {
4203 	copy_tv(argvars, rettv);
4204 	eval_index_inner(rettv, TRUE, argvars + 1,
4205 		argvars[2].v_type == VAR_UNKNOWN ? NULL : argvars + 2,
4206 		TRUE, NULL, 0, FALSE);
4207     }
4208 }
4209 
4210 /*
4211  * Apply index or range to "rettv".
4212  * "var1" is the first index, NULL for [:expr].
4213  * "var2" is the second index, NULL for [expr] and [expr: ]
4214  * "exclusive" is TRUE for slice(): second index is exclusive, use character
4215  * index for string.
4216  * Alternatively, "key" is not NULL, then key[keylen] is the dict index.
4217  */
4218     int
4219 eval_index_inner(
4220 	typval_T    *rettv,
4221 	int	    is_range,
4222 	typval_T    *var1,
4223 	typval_T    *var2,
4224 	int	    exclusive,
4225 	char_u	    *key,
4226 	int	    keylen,
4227 	int	    verbose)
4228 {
4229     varnumber_T	    n1, n2 = 0;
4230     long	    len;
4231 
4232     n1 = 0;
4233     if (var1 != NULL && rettv->v_type != VAR_DICT)
4234 	n1 = tv_get_number(var1);
4235 
4236     if (is_range)
4237     {
4238 	if (rettv->v_type == VAR_DICT)
4239 	{
4240 	    if (verbose)
4241 		emsg(_(e_cannot_slice_dictionary));
4242 	    return FAIL;
4243 	}
4244 	if (var2 != NULL)
4245 	    n2 = tv_get_number(var2);
4246 	else
4247 	    n2 = VARNUM_MAX;
4248     }
4249 
4250     switch (rettv->v_type)
4251     {
4252 	case VAR_UNKNOWN:
4253 	case VAR_ANY:
4254 	case VAR_VOID:
4255 	case VAR_FUNC:
4256 	case VAR_PARTIAL:
4257 	case VAR_FLOAT:
4258 	case VAR_BOOL:
4259 	case VAR_SPECIAL:
4260 	case VAR_JOB:
4261 	case VAR_CHANNEL:
4262 	case VAR_INSTR:
4263 	    break; // not evaluating, skipping over subscript
4264 
4265 	case VAR_NUMBER:
4266 	case VAR_STRING:
4267 	    {
4268 		char_u	*s = tv_get_string(rettv);
4269 
4270 		len = (long)STRLEN(s);
4271 		if (in_vim9script() || exclusive)
4272 		{
4273 		    if (is_range)
4274 			s = string_slice(s, n1, n2, exclusive);
4275 		    else
4276 			s = char_from_string(s, n1);
4277 		}
4278 		else if (is_range)
4279 		{
4280 		    // The resulting variable is a substring.  If the indexes
4281 		    // are out of range the result is empty.
4282 		    if (n1 < 0)
4283 		    {
4284 			n1 = len + n1;
4285 			if (n1 < 0)
4286 			    n1 = 0;
4287 		    }
4288 		    if (n2 < 0)
4289 			n2 = len + n2;
4290 		    else if (n2 >= len)
4291 			n2 = len;
4292 		    if (n1 >= len || n2 < 0 || n1 > n2)
4293 			s = NULL;
4294 		    else
4295 			s = vim_strnsave(s + n1, n2 - n1 + 1);
4296 		}
4297 		else
4298 		{
4299 		    // The resulting variable is a string of a single
4300 		    // character.  If the index is too big or negative the
4301 		    // result is empty.
4302 		    if (n1 >= len || n1 < 0)
4303 			s = NULL;
4304 		    else
4305 			s = vim_strnsave(s + n1, 1);
4306 		}
4307 		clear_tv(rettv);
4308 		rettv->v_type = VAR_STRING;
4309 		rettv->vval.v_string = s;
4310 	    }
4311 	    break;
4312 
4313 	case VAR_BLOB:
4314 	    blob_slice_or_index(rettv->vval.v_blob, is_range, n1, n2,
4315 							     exclusive, rettv);
4316 	    break;
4317 
4318 	case VAR_LIST:
4319 	    if (var1 == NULL)
4320 		n1 = 0;
4321 	    if (var2 == NULL)
4322 		n2 = VARNUM_MAX;
4323 	    if (list_slice_or_index(rettv->vval.v_list,
4324 			  is_range, n1, n2, exclusive, rettv, verbose) == FAIL)
4325 		return FAIL;
4326 	    break;
4327 
4328 	case VAR_DICT:
4329 	    {
4330 		dictitem_T	*item;
4331 		typval_T	tmp;
4332 
4333 		if (key == NULL)
4334 		{
4335 		    key = tv_get_string_chk(var1);
4336 		    if (key == NULL)
4337 			return FAIL;
4338 		}
4339 
4340 		item = dict_find(rettv->vval.v_dict, key, (int)keylen);
4341 
4342 		if (item == NULL && verbose)
4343 		    semsg(_(e_dictkey), key);
4344 		if (item == NULL)
4345 		    return FAIL;
4346 
4347 		copy_tv(&item->di_tv, &tmp);
4348 		clear_tv(rettv);
4349 		*rettv = tmp;
4350 	    }
4351 	    break;
4352     }
4353     return OK;
4354 }
4355 
4356 /*
4357  * Return the function name of partial "pt".
4358  */
4359     char_u *
4360 partial_name(partial_T *pt)
4361 {
4362     if (pt != NULL)
4363     {
4364 	if (pt->pt_name != NULL)
4365 	    return pt->pt_name;
4366 	if (pt->pt_func != NULL)
4367 	    return pt->pt_func->uf_name;
4368     }
4369     return (char_u *)"";
4370 }
4371 
4372     static void
4373 partial_free(partial_T *pt)
4374 {
4375     int i;
4376 
4377     for (i = 0; i < pt->pt_argc; ++i)
4378 	clear_tv(&pt->pt_argv[i]);
4379     vim_free(pt->pt_argv);
4380     dict_unref(pt->pt_dict);
4381     if (pt->pt_name != NULL)
4382     {
4383 	func_unref(pt->pt_name);
4384 	vim_free(pt->pt_name);
4385     }
4386     else
4387 	func_ptr_unref(pt->pt_func);
4388 
4389     // "out_up" is no longer used, decrement refcount on partial that owns it.
4390     partial_unref(pt->pt_outer.out_up_partial);
4391 
4392     // Decrease the reference count for the context of a closure.  If down
4393     // to the minimum it may be time to free it.
4394     if (pt->pt_funcstack != NULL)
4395     {
4396 	--pt->pt_funcstack->fs_refcount;
4397 	funcstack_check_refcount(pt->pt_funcstack);
4398     }
4399 
4400     vim_free(pt);
4401 }
4402 
4403 /*
4404  * Unreference a closure: decrement the reference count and free it when it
4405  * becomes zero.
4406  */
4407     void
4408 partial_unref(partial_T *pt)
4409 {
4410     if (pt != NULL)
4411     {
4412 	if (--pt->pt_refcount <= 0)
4413 	    partial_free(pt);
4414 
4415 	// If the reference count goes down to one, the funcstack may be the
4416 	// only reference and can be freed if no other partials reference it.
4417 	else if (pt->pt_refcount == 1 && pt->pt_funcstack != NULL)
4418 	    funcstack_check_refcount(pt->pt_funcstack);
4419     }
4420 }
4421 
4422 /*
4423  * Return the next (unique) copy ID.
4424  * Used for serializing nested structures.
4425  */
4426     int
4427 get_copyID(void)
4428 {
4429     current_copyID += COPYID_INC;
4430     return current_copyID;
4431 }
4432 
4433 /*
4434  * Garbage collection for lists and dictionaries.
4435  *
4436  * We use reference counts to be able to free most items right away when they
4437  * are no longer used.  But for composite items it's possible that it becomes
4438  * unused while the reference count is > 0: When there is a recursive
4439  * reference.  Example:
4440  *	:let l = [1, 2, 3]
4441  *	:let d = {9: l}
4442  *	:let l[1] = d
4443  *
4444  * Since this is quite unusual we handle this with garbage collection: every
4445  * once in a while find out which lists and dicts are not referenced from any
4446  * variable.
4447  *
4448  * Here is a good reference text about garbage collection (refers to Python
4449  * but it applies to all reference-counting mechanisms):
4450  *	http://python.ca/nas/python/gc/
4451  */
4452 
4453 /*
4454  * Do garbage collection for lists and dicts.
4455  * When "testing" is TRUE this is called from test_garbagecollect_now().
4456  * Return TRUE if some memory was freed.
4457  */
4458     int
4459 garbage_collect(int testing)
4460 {
4461     int		copyID;
4462     int		abort = FALSE;
4463     buf_T	*buf;
4464     win_T	*wp;
4465     int		did_free = FALSE;
4466     tabpage_T	*tp;
4467 
4468     if (!testing)
4469     {
4470 	// Only do this once.
4471 	want_garbage_collect = FALSE;
4472 	may_garbage_collect = FALSE;
4473 	garbage_collect_at_exit = FALSE;
4474     }
4475 
4476     // The execution stack can grow big, limit the size.
4477     if (exestack.ga_maxlen - exestack.ga_len > 500)
4478     {
4479 	size_t	new_len;
4480 	char_u	*pp;
4481 	int	n;
4482 
4483 	// Keep 150% of the current size, with a minimum of the growth size.
4484 	n = exestack.ga_len / 2;
4485 	if (n < exestack.ga_growsize)
4486 	    n = exestack.ga_growsize;
4487 
4488 	// Don't make it bigger though.
4489 	if (exestack.ga_len + n < exestack.ga_maxlen)
4490 	{
4491 	    new_len = exestack.ga_itemsize * (exestack.ga_len + n);
4492 	    pp = vim_realloc(exestack.ga_data, new_len);
4493 	    if (pp == NULL)
4494 		return FAIL;
4495 	    exestack.ga_maxlen = exestack.ga_len + n;
4496 	    exestack.ga_data = pp;
4497 	}
4498     }
4499 
4500     // We advance by two because we add one for items referenced through
4501     // previous_funccal.
4502     copyID = get_copyID();
4503 
4504     /*
4505      * 1. Go through all accessible variables and mark all lists and dicts
4506      *    with copyID.
4507      */
4508 
4509     // Don't free variables in the previous_funccal list unless they are only
4510     // referenced through previous_funccal.  This must be first, because if
4511     // the item is referenced elsewhere the funccal must not be freed.
4512     abort = abort || set_ref_in_previous_funccal(copyID);
4513 
4514     // script-local variables
4515     abort = abort || garbage_collect_scriptvars(copyID);
4516 
4517     // buffer-local variables
4518     FOR_ALL_BUFFERS(buf)
4519 	abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID,
4520 								  NULL, NULL);
4521 
4522     // window-local variables
4523     FOR_ALL_TAB_WINDOWS(tp, wp)
4524 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4525 								  NULL, NULL);
4526     if (aucmd_win != NULL)
4527 	abort = abort || set_ref_in_item(&aucmd_win->w_winvar.di_tv, copyID,
4528 								  NULL, NULL);
4529 #ifdef FEAT_PROP_POPUP
4530     FOR_ALL_POPUPWINS(wp)
4531 	abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4532 								  NULL, NULL);
4533     FOR_ALL_TABPAGES(tp)
4534 	FOR_ALL_POPUPWINS_IN_TAB(tp, wp)
4535 		abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID,
4536 								  NULL, NULL);
4537 #endif
4538 
4539     // tabpage-local variables
4540     FOR_ALL_TABPAGES(tp)
4541 	abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID,
4542 								  NULL, NULL);
4543     // global variables
4544     abort = abort || garbage_collect_globvars(copyID);
4545 
4546     // function-local variables
4547     abort = abort || set_ref_in_call_stack(copyID);
4548 
4549     // named functions (matters for closures)
4550     abort = abort || set_ref_in_functions(copyID);
4551 
4552     // function call arguments, if v:testing is set.
4553     abort = abort || set_ref_in_func_args(copyID);
4554 
4555     // v: vars
4556     abort = abort || garbage_collect_vimvars(copyID);
4557 
4558     // callbacks in buffers
4559     abort = abort || set_ref_in_buffers(copyID);
4560 
4561 #ifdef FEAT_LUA
4562     abort = abort || set_ref_in_lua(copyID);
4563 #endif
4564 
4565 #ifdef FEAT_PYTHON
4566     abort = abort || set_ref_in_python(copyID);
4567 #endif
4568 
4569 #ifdef FEAT_PYTHON3
4570     abort = abort || set_ref_in_python3(copyID);
4571 #endif
4572 
4573 #ifdef FEAT_JOB_CHANNEL
4574     abort = abort || set_ref_in_channel(copyID);
4575     abort = abort || set_ref_in_job(copyID);
4576 #endif
4577 #ifdef FEAT_NETBEANS_INTG
4578     abort = abort || set_ref_in_nb_channel(copyID);
4579 #endif
4580 
4581 #ifdef FEAT_TIMERS
4582     abort = abort || set_ref_in_timer(copyID);
4583 #endif
4584 
4585 #ifdef FEAT_QUICKFIX
4586     abort = abort || set_ref_in_quickfix(copyID);
4587 #endif
4588 
4589 #ifdef FEAT_TERMINAL
4590     abort = abort || set_ref_in_term(copyID);
4591 #endif
4592 
4593 #ifdef FEAT_PROP_POPUP
4594     abort = abort || set_ref_in_popups(copyID);
4595 #endif
4596 
4597     if (!abort)
4598     {
4599 	/*
4600 	 * 2. Free lists and dictionaries that are not referenced.
4601 	 */
4602 	did_free = free_unref_items(copyID);
4603 
4604 	/*
4605 	 * 3. Check if any funccal can be freed now.
4606 	 *    This may call us back recursively.
4607 	 */
4608 	free_unref_funccal(copyID, testing);
4609     }
4610     else if (p_verbose > 0)
4611     {
4612 	verb_msg(_("Not enough memory to set references, garbage collection aborted!"));
4613     }
4614 
4615     return did_free;
4616 }
4617 
4618 /*
4619  * Free lists, dictionaries, channels and jobs that are no longer referenced.
4620  */
4621     static int
4622 free_unref_items(int copyID)
4623 {
4624     int		did_free = FALSE;
4625 
4626     // Let all "free" functions know that we are here.  This means no
4627     // dictionaries, lists, channels or jobs are to be freed, because we will
4628     // do that here.
4629     in_free_unref_items = TRUE;
4630 
4631     /*
4632      * PASS 1: free the contents of the items.  We don't free the items
4633      * themselves yet, so that it is possible to decrement refcount counters
4634      */
4635 
4636     // Go through the list of dicts and free items without the copyID.
4637     did_free |= dict_free_nonref(copyID);
4638 
4639     // Go through the list of lists and free items without the copyID.
4640     did_free |= list_free_nonref(copyID);
4641 
4642 #ifdef FEAT_JOB_CHANNEL
4643     // Go through the list of jobs and free items without the copyID. This
4644     // must happen before doing channels, because jobs refer to channels, but
4645     // the reference from the channel to the job isn't tracked.
4646     did_free |= free_unused_jobs_contents(copyID, COPYID_MASK);
4647 
4648     // Go through the list of channels and free items without the copyID.
4649     did_free |= free_unused_channels_contents(copyID, COPYID_MASK);
4650 #endif
4651 
4652     /*
4653      * PASS 2: free the items themselves.
4654      */
4655     dict_free_items(copyID);
4656     list_free_items(copyID);
4657 
4658 #ifdef FEAT_JOB_CHANNEL
4659     // Go through the list of jobs and free items without the copyID. This
4660     // must happen before doing channels, because jobs refer to channels, but
4661     // the reference from the channel to the job isn't tracked.
4662     free_unused_jobs(copyID, COPYID_MASK);
4663 
4664     // Go through the list of channels and free items without the copyID.
4665     free_unused_channels(copyID, COPYID_MASK);
4666 #endif
4667 
4668     in_free_unref_items = FALSE;
4669 
4670     return did_free;
4671 }
4672 
4673 /*
4674  * Mark all lists and dicts referenced through hashtab "ht" with "copyID".
4675  * "list_stack" is used to add lists to be marked.  Can be NULL.
4676  *
4677  * Returns TRUE if setting references failed somehow.
4678  */
4679     int
4680 set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack)
4681 {
4682     int		todo;
4683     int		abort = FALSE;
4684     hashitem_T	*hi;
4685     hashtab_T	*cur_ht;
4686     ht_stack_T	*ht_stack = NULL;
4687     ht_stack_T	*tempitem;
4688 
4689     cur_ht = ht;
4690     for (;;)
4691     {
4692 	if (!abort)
4693 	{
4694 	    // Mark each item in the hashtab.  If the item contains a hashtab
4695 	    // it is added to ht_stack, if it contains a list it is added to
4696 	    // list_stack.
4697 	    todo = (int)cur_ht->ht_used;
4698 	    for (hi = cur_ht->ht_array; todo > 0; ++hi)
4699 		if (!HASHITEM_EMPTY(hi))
4700 		{
4701 		    --todo;
4702 		    abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID,
4703 						       &ht_stack, list_stack);
4704 		}
4705 	}
4706 
4707 	if (ht_stack == NULL)
4708 	    break;
4709 
4710 	// take an item from the stack
4711 	cur_ht = ht_stack->ht;
4712 	tempitem = ht_stack;
4713 	ht_stack = ht_stack->prev;
4714 	free(tempitem);
4715     }
4716 
4717     return abort;
4718 }
4719 
4720 /*
4721  * Mark a dict and its items with "copyID".
4722  * Returns TRUE if setting references failed somehow.
4723  */
4724     int
4725 set_ref_in_dict(dict_T *d, int copyID)
4726 {
4727     if (d != NULL && d->dv_copyID != copyID)
4728     {
4729 	d->dv_copyID = copyID;
4730 	return set_ref_in_ht(&d->dv_hashtab, copyID, NULL);
4731     }
4732     return FALSE;
4733 }
4734 
4735 /*
4736  * Mark a list and its items with "copyID".
4737  * Returns TRUE if setting references failed somehow.
4738  */
4739     int
4740 set_ref_in_list(list_T *ll, int copyID)
4741 {
4742     if (ll != NULL && ll->lv_copyID != copyID)
4743     {
4744 	ll->lv_copyID = copyID;
4745 	return set_ref_in_list_items(ll, copyID, NULL);
4746     }
4747     return FALSE;
4748 }
4749 
4750 /*
4751  * Mark all lists and dicts referenced through list "l" with "copyID".
4752  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4753  *
4754  * Returns TRUE if setting references failed somehow.
4755  */
4756     int
4757 set_ref_in_list_items(list_T *l, int copyID, ht_stack_T **ht_stack)
4758 {
4759     listitem_T	 *li;
4760     int		 abort = FALSE;
4761     list_T	 *cur_l;
4762     list_stack_T *list_stack = NULL;
4763     list_stack_T *tempitem;
4764 
4765     cur_l = l;
4766     for (;;)
4767     {
4768 	if (!abort && cur_l->lv_first != &range_list_item)
4769 	    // Mark each item in the list.  If the item contains a hashtab
4770 	    // it is added to ht_stack, if it contains a list it is added to
4771 	    // list_stack.
4772 	    for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next)
4773 		abort = abort || set_ref_in_item(&li->li_tv, copyID,
4774 						       ht_stack, &list_stack);
4775 	if (list_stack == NULL)
4776 	    break;
4777 
4778 	// take an item from the stack
4779 	cur_l = list_stack->list;
4780 	tempitem = list_stack;
4781 	list_stack = list_stack->prev;
4782 	free(tempitem);
4783     }
4784 
4785     return abort;
4786 }
4787 
4788 /*
4789  * Mark all lists and dicts referenced through typval "tv" with "copyID".
4790  * "list_stack" is used to add lists to be marked.  Can be NULL.
4791  * "ht_stack" is used to add hashtabs to be marked.  Can be NULL.
4792  *
4793  * Returns TRUE if setting references failed somehow.
4794  */
4795     int
4796 set_ref_in_item(
4797     typval_T	    *tv,
4798     int		    copyID,
4799     ht_stack_T	    **ht_stack,
4800     list_stack_T    **list_stack)
4801 {
4802     int		abort = FALSE;
4803 
4804     if (tv->v_type == VAR_DICT)
4805     {
4806 	dict_T	*dd = tv->vval.v_dict;
4807 
4808 	if (dd != NULL && dd->dv_copyID != copyID)
4809 	{
4810 	    // Didn't see this dict yet.
4811 	    dd->dv_copyID = copyID;
4812 	    if (ht_stack == NULL)
4813 	    {
4814 		abort = set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack);
4815 	    }
4816 	    else
4817 	    {
4818 		ht_stack_T *newitem = ALLOC_ONE(ht_stack_T);
4819 
4820 		if (newitem == NULL)
4821 		    abort = TRUE;
4822 		else
4823 		{
4824 		    newitem->ht = &dd->dv_hashtab;
4825 		    newitem->prev = *ht_stack;
4826 		    *ht_stack = newitem;
4827 		}
4828 	    }
4829 	}
4830     }
4831     else if (tv->v_type == VAR_LIST)
4832     {
4833 	list_T	*ll = tv->vval.v_list;
4834 
4835 	if (ll != NULL && ll->lv_copyID != copyID)
4836 	{
4837 	    // Didn't see this list yet.
4838 	    ll->lv_copyID = copyID;
4839 	    if (list_stack == NULL)
4840 	    {
4841 		abort = set_ref_in_list_items(ll, copyID, ht_stack);
4842 	    }
4843 	    else
4844 	    {
4845 		list_stack_T *newitem = ALLOC_ONE(list_stack_T);
4846 
4847 		if (newitem == NULL)
4848 		    abort = TRUE;
4849 		else
4850 		{
4851 		    newitem->list = ll;
4852 		    newitem->prev = *list_stack;
4853 		    *list_stack = newitem;
4854 		}
4855 	    }
4856 	}
4857     }
4858     else if (tv->v_type == VAR_FUNC)
4859     {
4860 	abort = set_ref_in_func(tv->vval.v_string, NULL, copyID);
4861     }
4862     else if (tv->v_type == VAR_PARTIAL)
4863     {
4864 	partial_T	*pt = tv->vval.v_partial;
4865 	int		i;
4866 
4867 	if (pt != NULL && pt->pt_copyID != copyID)
4868 	{
4869 	    // Didn't see this partial yet.
4870 	    pt->pt_copyID = copyID;
4871 
4872 	    abort = set_ref_in_func(pt->pt_name, pt->pt_func, copyID);
4873 
4874 	    if (pt->pt_dict != NULL)
4875 	    {
4876 		typval_T dtv;
4877 
4878 		dtv.v_type = VAR_DICT;
4879 		dtv.vval.v_dict = pt->pt_dict;
4880 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4881 	    }
4882 
4883 	    for (i = 0; i < pt->pt_argc; ++i)
4884 		abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID,
4885 							ht_stack, list_stack);
4886 	    if (pt->pt_funcstack != NULL)
4887 	    {
4888 		typval_T    *stack = pt->pt_funcstack->fs_ga.ga_data;
4889 
4890 		for (i = 0; i < pt->pt_funcstack->fs_ga.ga_len; ++i)
4891 		    abort = abort || set_ref_in_item(stack + i, copyID,
4892 							 ht_stack, list_stack);
4893 	    }
4894 
4895 	}
4896     }
4897 #ifdef FEAT_JOB_CHANNEL
4898     else if (tv->v_type == VAR_JOB)
4899     {
4900 	job_T	    *job = tv->vval.v_job;
4901 	typval_T    dtv;
4902 
4903 	if (job != NULL && job->jv_copyID != copyID)
4904 	{
4905 	    job->jv_copyID = copyID;
4906 	    if (job->jv_channel != NULL)
4907 	    {
4908 		dtv.v_type = VAR_CHANNEL;
4909 		dtv.vval.v_channel = job->jv_channel;
4910 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4911 	    }
4912 	    if (job->jv_exit_cb.cb_partial != NULL)
4913 	    {
4914 		dtv.v_type = VAR_PARTIAL;
4915 		dtv.vval.v_partial = job->jv_exit_cb.cb_partial;
4916 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4917 	    }
4918 	}
4919     }
4920     else if (tv->v_type == VAR_CHANNEL)
4921     {
4922 	channel_T   *ch =tv->vval.v_channel;
4923 	ch_part_T   part;
4924 	typval_T    dtv;
4925 	jsonq_T	    *jq;
4926 	cbq_T	    *cq;
4927 
4928 	if (ch != NULL && ch->ch_copyID != copyID)
4929 	{
4930 	    ch->ch_copyID = copyID;
4931 	    for (part = PART_SOCK; part < PART_COUNT; ++part)
4932 	    {
4933 		for (jq = ch->ch_part[part].ch_json_head.jq_next; jq != NULL;
4934 							     jq = jq->jq_next)
4935 		    set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack);
4936 		for (cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL;
4937 							     cq = cq->cq_next)
4938 		    if (cq->cq_callback.cb_partial != NULL)
4939 		    {
4940 			dtv.v_type = VAR_PARTIAL;
4941 			dtv.vval.v_partial = cq->cq_callback.cb_partial;
4942 			set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4943 		    }
4944 		if (ch->ch_part[part].ch_callback.cb_partial != NULL)
4945 		{
4946 		    dtv.v_type = VAR_PARTIAL;
4947 		    dtv.vval.v_partial =
4948 				      ch->ch_part[part].ch_callback.cb_partial;
4949 		    set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4950 		}
4951 	    }
4952 	    if (ch->ch_callback.cb_partial != NULL)
4953 	    {
4954 		dtv.v_type = VAR_PARTIAL;
4955 		dtv.vval.v_partial = ch->ch_callback.cb_partial;
4956 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4957 	    }
4958 	    if (ch->ch_close_cb.cb_partial != NULL)
4959 	    {
4960 		dtv.v_type = VAR_PARTIAL;
4961 		dtv.vval.v_partial = ch->ch_close_cb.cb_partial;
4962 		set_ref_in_item(&dtv, copyID, ht_stack, list_stack);
4963 	    }
4964 	}
4965     }
4966 #endif
4967     return abort;
4968 }
4969 
4970 /*
4971  * Return a string with the string representation of a variable.
4972  * If the memory is allocated "tofree" is set to it, otherwise NULL.
4973  * "numbuf" is used for a number.
4974  * When "copyID" is not NULL replace recursive lists and dicts with "...".
4975  * When both "echo_style" and "composite_val" are FALSE, put quotes around
4976  * strings as "string()", otherwise does not put quotes around strings, as
4977  * ":echo" displays values.
4978  * When "restore_copyID" is FALSE, repeated items in dictionaries and lists
4979  * are replaced with "...".
4980  * May return NULL.
4981  */
4982     char_u *
4983 echo_string_core(
4984     typval_T	*tv,
4985     char_u	**tofree,
4986     char_u	*numbuf,
4987     int		copyID,
4988     int		echo_style,
4989     int		restore_copyID,
4990     int		composite_val)
4991 {
4992     static int	recurse = 0;
4993     char_u	*r = NULL;
4994 
4995     if (recurse >= DICT_MAXNEST)
4996     {
4997 	if (!did_echo_string_emsg)
4998 	{
4999 	    // Only give this message once for a recursive call to avoid
5000 	    // flooding the user with errors.  And stop iterating over lists
5001 	    // and dicts.
5002 	    did_echo_string_emsg = TRUE;
5003 	    emsg(_("E724: variable nested too deep for displaying"));
5004 	}
5005 	*tofree = NULL;
5006 	return (char_u *)"{E724}";
5007     }
5008     ++recurse;
5009 
5010     switch (tv->v_type)
5011     {
5012 	case VAR_STRING:
5013 	    if (echo_style && !composite_val)
5014 	    {
5015 		*tofree = NULL;
5016 		r = tv->vval.v_string;
5017 		if (r == NULL)
5018 		    r = (char_u *)"";
5019 	    }
5020 	    else
5021 	    {
5022 		*tofree = string_quote(tv->vval.v_string, FALSE);
5023 		r = *tofree;
5024 	    }
5025 	    break;
5026 
5027 	case VAR_FUNC:
5028 	    if (echo_style)
5029 	    {
5030 		*tofree = NULL;
5031 		r = tv->vval.v_string;
5032 	    }
5033 	    else
5034 	    {
5035 		*tofree = string_quote(tv->vval.v_string, TRUE);
5036 		r = *tofree;
5037 	    }
5038 	    break;
5039 
5040 	case VAR_PARTIAL:
5041 	    {
5042 		partial_T   *pt = tv->vval.v_partial;
5043 		char_u	    *fname = string_quote(pt == NULL ? NULL
5044 						    : partial_name(pt), FALSE);
5045 		garray_T    ga;
5046 		int	    i;
5047 		char_u	    *tf;
5048 
5049 		ga_init2(&ga, 1, 100);
5050 		ga_concat(&ga, (char_u *)"function(");
5051 		if (fname != NULL)
5052 		{
5053 		    ga_concat(&ga, fname);
5054 		    vim_free(fname);
5055 		}
5056 		if (pt != NULL && pt->pt_argc > 0)
5057 		{
5058 		    ga_concat(&ga, (char_u *)", [");
5059 		    for (i = 0; i < pt->pt_argc; ++i)
5060 		    {
5061 			if (i > 0)
5062 			    ga_concat(&ga, (char_u *)", ");
5063 			ga_concat(&ga,
5064 			     tv2string(&pt->pt_argv[i], &tf, numbuf, copyID));
5065 			vim_free(tf);
5066 		    }
5067 		    ga_concat(&ga, (char_u *)"]");
5068 		}
5069 		if (pt != NULL && pt->pt_dict != NULL)
5070 		{
5071 		    typval_T dtv;
5072 
5073 		    ga_concat(&ga, (char_u *)", ");
5074 		    dtv.v_type = VAR_DICT;
5075 		    dtv.vval.v_dict = pt->pt_dict;
5076 		    ga_concat(&ga, tv2string(&dtv, &tf, numbuf, copyID));
5077 		    vim_free(tf);
5078 		}
5079 		ga_concat(&ga, (char_u *)")");
5080 
5081 		*tofree = ga.ga_data;
5082 		r = *tofree;
5083 		break;
5084 	    }
5085 
5086 	case VAR_BLOB:
5087 	    r = blob2string(tv->vval.v_blob, tofree, numbuf);
5088 	    break;
5089 
5090 	case VAR_LIST:
5091 	    if (tv->vval.v_list == NULL)
5092 	    {
5093 		// NULL list is equivalent to empty list.
5094 		*tofree = NULL;
5095 		r = (char_u *)"[]";
5096 	    }
5097 	    else if (copyID != 0 && tv->vval.v_list->lv_copyID == copyID
5098 		    && tv->vval.v_list->lv_len > 0)
5099 	    {
5100 		*tofree = NULL;
5101 		r = (char_u *)"[...]";
5102 	    }
5103 	    else
5104 	    {
5105 		int old_copyID = tv->vval.v_list->lv_copyID;
5106 
5107 		tv->vval.v_list->lv_copyID = copyID;
5108 		*tofree = list2string(tv, copyID, restore_copyID);
5109 		if (restore_copyID)
5110 		    tv->vval.v_list->lv_copyID = old_copyID;
5111 		r = *tofree;
5112 	    }
5113 	    break;
5114 
5115 	case VAR_DICT:
5116 	    if (tv->vval.v_dict == NULL)
5117 	    {
5118 		// NULL dict is equivalent to empty dict.
5119 		*tofree = NULL;
5120 		r = (char_u *)"{}";
5121 	    }
5122 	    else if (copyID != 0 && tv->vval.v_dict->dv_copyID == copyID
5123 		    && tv->vval.v_dict->dv_hashtab.ht_used != 0)
5124 	    {
5125 		*tofree = NULL;
5126 		r = (char_u *)"{...}";
5127 	    }
5128 	    else
5129 	    {
5130 		int old_copyID = tv->vval.v_dict->dv_copyID;
5131 
5132 		tv->vval.v_dict->dv_copyID = copyID;
5133 		*tofree = dict2string(tv, copyID, restore_copyID);
5134 		if (restore_copyID)
5135 		    tv->vval.v_dict->dv_copyID = old_copyID;
5136 		r = *tofree;
5137 	    }
5138 	    break;
5139 
5140 	case VAR_NUMBER:
5141 	case VAR_UNKNOWN:
5142 	case VAR_ANY:
5143 	case VAR_VOID:
5144 	    *tofree = NULL;
5145 	    r = tv_get_string_buf(tv, numbuf);
5146 	    break;
5147 
5148 	case VAR_JOB:
5149 	case VAR_CHANNEL:
5150 #ifdef FEAT_JOB_CHANNEL
5151 	    *tofree = NULL;
5152 	    r = tv->v_type == VAR_JOB ? job_to_string_buf(tv, numbuf)
5153 					   : channel_to_string_buf(tv, numbuf);
5154 	    if (composite_val)
5155 	    {
5156 		*tofree = string_quote(r, FALSE);
5157 		r = *tofree;
5158 	    }
5159 #endif
5160 	    break;
5161 
5162 	case VAR_INSTR:
5163 	    *tofree = NULL;
5164 	    r = (char_u *)"instructions";
5165 	    break;
5166 
5167 	case VAR_FLOAT:
5168 #ifdef FEAT_FLOAT
5169 	    *tofree = NULL;
5170 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%g", tv->vval.v_float);
5171 	    r = numbuf;
5172 	    break;
5173 #endif
5174 
5175 	case VAR_BOOL:
5176 	case VAR_SPECIAL:
5177 	    *tofree = NULL;
5178 	    r = (char_u *)get_var_special_name(tv->vval.v_number);
5179 	    break;
5180     }
5181 
5182     if (--recurse == 0)
5183 	did_echo_string_emsg = FALSE;
5184     return r;
5185 }
5186 
5187 /*
5188  * Return a string with the string representation of a variable.
5189  * If the memory is allocated "tofree" is set to it, otherwise NULL.
5190  * "numbuf" is used for a number.
5191  * Does not put quotes around strings, as ":echo" displays values.
5192  * When "copyID" is not NULL replace recursive lists and dicts with "...".
5193  * May return NULL.
5194  */
5195     char_u *
5196 echo_string(
5197     typval_T	*tv,
5198     char_u	**tofree,
5199     char_u	*numbuf,
5200     int		copyID)
5201 {
5202     return echo_string_core(tv, tofree, numbuf, copyID, TRUE, FALSE, FALSE);
5203 }
5204 
5205 /*
5206  * Convert the specified byte index of line 'lnum' in buffer 'buf' to a
5207  * character index.  Works only for loaded buffers. Returns -1 on failure.
5208  * The index of the first byte and the first character is zero.
5209  */
5210     int
5211 buf_byteidx_to_charidx(buf_T *buf, int lnum, int byteidx)
5212 {
5213     char_u	*str;
5214     char_u	*t;
5215     int		count;
5216 
5217     if (buf == NULL || buf->b_ml.ml_mfp == NULL)
5218 	return -1;
5219 
5220     if (lnum > buf->b_ml.ml_line_count)
5221 	lnum = buf->b_ml.ml_line_count;
5222 
5223     str = ml_get_buf(buf, lnum, FALSE);
5224     if (str == NULL)
5225 	return -1;
5226 
5227     if (*str == NUL)
5228 	return 0;
5229 
5230     // count the number of characters
5231     t = str;
5232     for (count = 0; *t != NUL && t <= str + byteidx; count++)
5233 	t += mb_ptr2len(t);
5234 
5235     // In insert mode, when the cursor is at the end of a non-empty line,
5236     // byteidx points to the NUL character immediately past the end of the
5237     // string. In this case, add one to the character count.
5238     if (*t == NUL && byteidx != 0 && t == str + byteidx)
5239 	count++;
5240 
5241     return count - 1;
5242 }
5243 
5244 /*
5245  * Convert the specified character index of line 'lnum' in buffer 'buf' to a
5246  * byte index.  Works only for loaded buffers. Returns -1 on failure.
5247  * The index of the first byte and the first character is zero.
5248  */
5249     int
5250 buf_charidx_to_byteidx(buf_T *buf, int lnum, int charidx)
5251 {
5252     char_u	*str;
5253     char_u	*t;
5254 
5255     if (buf == NULL || buf->b_ml.ml_mfp == NULL)
5256 	return -1;
5257 
5258     if (lnum > buf->b_ml.ml_line_count)
5259 	lnum = buf->b_ml.ml_line_count;
5260 
5261     str = ml_get_buf(buf, lnum, FALSE);
5262     if (str == NULL)
5263 	return -1;
5264 
5265     // Convert the character offset to a byte offset
5266     t = str;
5267     while (*t != NUL && --charidx > 0)
5268 	t += mb_ptr2len(t);
5269 
5270     return t - str;
5271 }
5272 
5273 /*
5274  * Translate a String variable into a position.
5275  * Returns NULL when there is an error.
5276  */
5277     pos_T *
5278 var2fpos(
5279     typval_T	*varp,
5280     int		dollar_lnum,	// TRUE when $ is last line
5281     int		*fnum,		// set to fnum for '0, 'A, etc.
5282     int		charcol)	// return character column
5283 {
5284     char_u		*name;
5285     static pos_T	pos;
5286     pos_T		*pp;
5287 
5288     // Argument can be [lnum, col, coladd].
5289     if (varp->v_type == VAR_LIST)
5290     {
5291 	list_T		*l;
5292 	int		len;
5293 	int		error = FALSE;
5294 	listitem_T	*li;
5295 
5296 	l = varp->vval.v_list;
5297 	if (l == NULL)
5298 	    return NULL;
5299 
5300 	// Get the line number
5301 	pos.lnum = list_find_nr(l, 0L, &error);
5302 	if (error || pos.lnum <= 0 || pos.lnum > curbuf->b_ml.ml_line_count)
5303 	    return NULL;	// invalid line number
5304 	if (charcol)
5305 	    len = (long)mb_charlen(ml_get(pos.lnum));
5306 	else
5307 	    len = (long)STRLEN(ml_get(pos.lnum));
5308 
5309 	// Get the column number
5310 	// We accept "$" for the column number: last column.
5311 	li = list_find(l, 1L);
5312 	if (li != NULL && li->li_tv.v_type == VAR_STRING
5313 		&& li->li_tv.vval.v_string != NULL
5314 		&& STRCMP(li->li_tv.vval.v_string, "$") == 0)
5315 	{
5316 	    pos.col = len + 1;
5317 	}
5318 	else
5319 	{
5320 	    pos.col = list_find_nr(l, 1L, &error);
5321 	    if (error)
5322 		return NULL;
5323 	}
5324 
5325 	// Accept a position up to the NUL after the line.
5326 	if (pos.col == 0 || (int)pos.col > len + 1)
5327 	    return NULL;	// invalid column number
5328 	--pos.col;
5329 
5330 	// Get the virtual offset.  Defaults to zero.
5331 	pos.coladd = list_find_nr(l, 2L, &error);
5332 	if (error)
5333 	    pos.coladd = 0;
5334 
5335 	return &pos;
5336     }
5337 
5338     if (in_vim9script() && check_for_string_arg(varp, 0) == FAIL)
5339 	return NULL;
5340 
5341     name = tv_get_string_chk(varp);
5342     if (name == NULL)
5343 	return NULL;
5344     if (name[0] == '.')				// cursor
5345     {
5346 	pos = curwin->w_cursor;
5347 	if (charcol)
5348 	    pos.col = buf_byteidx_to_charidx(curbuf, pos.lnum, pos.col);
5349 	return &pos;
5350     }
5351     if (name[0] == 'v' && name[1] == NUL)	// Visual start
5352     {
5353 	if (VIsual_active)
5354 	    pos = VIsual;
5355 	else
5356 	    pos = curwin->w_cursor;
5357 	if (charcol)
5358 	    pos.col = buf_byteidx_to_charidx(curbuf, pos.lnum, pos.col);
5359 	return &pos;
5360     }
5361     if (name[0] == '\'')			// mark
5362     {
5363 	pp = getmark_buf_fnum(curbuf, name[1], FALSE, fnum);
5364 	if (pp == NULL || pp == (pos_T *)-1 || pp->lnum <= 0)
5365 	    return NULL;
5366 	if (charcol)
5367 	    pp->col = buf_byteidx_to_charidx(curbuf, pp->lnum, pp->col);
5368 	return pp;
5369     }
5370 
5371     pos.coladd = 0;
5372 
5373     if (name[0] == 'w' && dollar_lnum)
5374     {
5375 	pos.col = 0;
5376 	if (name[1] == '0')		// "w0": first visible line
5377 	{
5378 	    update_topline();
5379 	    // In silent Ex mode topline is zero, but that's not a valid line
5380 	    // number; use one instead.
5381 	    pos.lnum = curwin->w_topline > 0 ? curwin->w_topline : 1;
5382 	    return &pos;
5383 	}
5384 	else if (name[1] == '$')	// "w$": last visible line
5385 	{
5386 	    validate_botline();
5387 	    // In silent Ex mode botline is zero, return zero then.
5388 	    pos.lnum = curwin->w_botline > 0 ? curwin->w_botline - 1 : 0;
5389 	    return &pos;
5390 	}
5391     }
5392     else if (name[0] == '$')		// last column or line
5393     {
5394 	if (dollar_lnum)
5395 	{
5396 	    pos.lnum = curbuf->b_ml.ml_line_count;
5397 	    pos.col = 0;
5398 	}
5399 	else
5400 	{
5401 	    pos.lnum = curwin->w_cursor.lnum;
5402 	    if (charcol)
5403 		pos.col = (colnr_T)mb_charlen(ml_get_curline());
5404 	    else
5405 		pos.col = (colnr_T)STRLEN(ml_get_curline());
5406 	}
5407 	return &pos;
5408     }
5409     if (in_vim9script())
5410 	semsg(_(e_invalid_value_for_line_number_str), name);
5411     return NULL;
5412 }
5413 
5414 /*
5415  * Convert list in "arg" into a position and optional file number.
5416  * When "fnump" is NULL there is no file number, only 3 items.
5417  * Note that the column is passed on as-is, the caller may want to decrement
5418  * it to use 1 for the first column.
5419  * Return FAIL when conversion is not possible, doesn't check the position for
5420  * validity.
5421  */
5422     int
5423 list2fpos(
5424     typval_T	*arg,
5425     pos_T	*posp,
5426     int		*fnump,
5427     colnr_T	*curswantp,
5428     int		charcol)
5429 {
5430     list_T	*l = arg->vval.v_list;
5431     long	i = 0;
5432     long	n;
5433 
5434     // List must be: [fnum, lnum, col, coladd, curswant], where "fnum" is only
5435     // there when "fnump" isn't NULL; "coladd" and "curswant" are optional.
5436     if (arg->v_type != VAR_LIST
5437 	    || l == NULL
5438 	    || l->lv_len < (fnump == NULL ? 2 : 3)
5439 	    || l->lv_len > (fnump == NULL ? 4 : 5))
5440 	return FAIL;
5441 
5442     if (fnump != NULL)
5443     {
5444 	n = list_find_nr(l, i++, NULL);	// fnum
5445 	if (n < 0)
5446 	    return FAIL;
5447 	if (n == 0)
5448 	    n = curbuf->b_fnum;		// current buffer
5449 	*fnump = n;
5450     }
5451 
5452     n = list_find_nr(l, i++, NULL);	// lnum
5453     if (n < 0)
5454 	return FAIL;
5455     posp->lnum = n;
5456 
5457     n = list_find_nr(l, i++, NULL);	// col
5458     if (n < 0)
5459 	return FAIL;
5460     // If character position is specified, then convert to byte position
5461     if (charcol)
5462     {
5463 	buf_T	*buf;
5464 
5465 	// Get the text for the specified line in a loaded buffer
5466 	buf = buflist_findnr(fnump == NULL ? curbuf->b_fnum : *fnump);
5467 	if (buf == NULL || buf->b_ml.ml_mfp == NULL)
5468 	    return FAIL;
5469 
5470 	n = buf_charidx_to_byteidx(buf, posp->lnum, n) + 1;
5471     }
5472     posp->col = n;
5473 
5474     n = list_find_nr(l, i, NULL);	// off
5475     if (n < 0)
5476 	posp->coladd = 0;
5477     else
5478 	posp->coladd = n;
5479 
5480     if (curswantp != NULL)
5481 	*curswantp = list_find_nr(l, i + 1, NULL);  // curswant
5482 
5483     return OK;
5484 }
5485 
5486 /*
5487  * Get the length of an environment variable name.
5488  * Advance "arg" to the first character after the name.
5489  * Return 0 for error.
5490  */
5491     int
5492 get_env_len(char_u **arg)
5493 {
5494     char_u	*p;
5495     int		len;
5496 
5497     for (p = *arg; vim_isIDc(*p); ++p)
5498 	;
5499     if (p == *arg)	    // no name found
5500 	return 0;
5501 
5502     len = (int)(p - *arg);
5503     *arg = p;
5504     return len;
5505 }
5506 
5507 /*
5508  * Get the length of the name of a function or internal variable.
5509  * "arg" is advanced to after the name.
5510  * Return 0 if something is wrong.
5511  */
5512     int
5513 get_id_len(char_u **arg)
5514 {
5515     char_u	*p;
5516     int		len;
5517 
5518     // Find the end of the name.
5519     for (p = *arg; eval_isnamec(*p); ++p)
5520     {
5521 	if (*p == ':')
5522 	{
5523 	    // "s:" is start of "s:var", but "n:" is not and can be used in
5524 	    // slice "[n:]".  Also "xx:" is not a namespace.
5525 	    len = (int)(p - *arg);
5526 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
5527 		    || len > 1)
5528 		break;
5529 	}
5530     }
5531     if (p == *arg)	    // no name found
5532 	return 0;
5533 
5534     len = (int)(p - *arg);
5535     *arg = p;
5536 
5537     return len;
5538 }
5539 
5540 /*
5541  * Get the length of the name of a variable or function.
5542  * Only the name is recognized, does not handle ".key" or "[idx]".
5543  * "arg" is advanced to the first non-white character after the name.
5544  * Return -1 if curly braces expansion failed.
5545  * Return 0 if something else is wrong.
5546  * If the name contains 'magic' {}'s, expand them and return the
5547  * expanded name in an allocated string via 'alias' - caller must free.
5548  */
5549     int
5550 get_name_len(
5551     char_u	**arg,
5552     char_u	**alias,
5553     int		evaluate,
5554     int		verbose)
5555 {
5556     int		len;
5557     char_u	*p;
5558     char_u	*expr_start;
5559     char_u	*expr_end;
5560 
5561     *alias = NULL;  // default to no alias
5562 
5563     if ((*arg)[0] == K_SPECIAL && (*arg)[1] == KS_EXTRA
5564 						  && (*arg)[2] == (int)KE_SNR)
5565     {
5566 	// hard coded <SNR>, already translated
5567 	*arg += 3;
5568 	return get_id_len(arg) + 3;
5569     }
5570     len = eval_fname_script(*arg);
5571     if (len > 0)
5572     {
5573 	// literal "<SID>", "s:" or "<SNR>"
5574 	*arg += len;
5575     }
5576 
5577     /*
5578      * Find the end of the name; check for {} construction.
5579      */
5580     p = find_name_end(*arg, &expr_start, &expr_end,
5581 					       len > 0 ? 0 : FNE_CHECK_START);
5582     if (expr_start != NULL)
5583     {
5584 	char_u	*temp_string;
5585 
5586 	if (!evaluate)
5587 	{
5588 	    len += (int)(p - *arg);
5589 	    *arg = skipwhite(p);
5590 	    return len;
5591 	}
5592 
5593 	/*
5594 	 * Include any <SID> etc in the expanded string:
5595 	 * Thus the -len here.
5596 	 */
5597 	temp_string = make_expanded_name(*arg - len, expr_start, expr_end, p);
5598 	if (temp_string == NULL)
5599 	    return -1;
5600 	*alias = temp_string;
5601 	*arg = skipwhite(p);
5602 	return (int)STRLEN(temp_string);
5603     }
5604 
5605     len += get_id_len(arg);
5606     // Only give an error when there is something, otherwise it will be
5607     // reported at a higher level.
5608     if (len == 0 && verbose && **arg != NUL)
5609 	semsg(_(e_invalid_expression_str), *arg);
5610 
5611     return len;
5612 }
5613 
5614 /*
5615  * Find the end of a variable or function name, taking care of magic braces.
5616  * If "expr_start" is not NULL then "expr_start" and "expr_end" are set to the
5617  * start and end of the first magic braces item.
5618  * "flags" can have FNE_INCL_BR and FNE_CHECK_START.
5619  * Return a pointer to just after the name.  Equal to "arg" if there is no
5620  * valid name.
5621  */
5622     char_u *
5623 find_name_end(
5624     char_u	*arg,
5625     char_u	**expr_start,
5626     char_u	**expr_end,
5627     int		flags)
5628 {
5629     int		mb_nest = 0;
5630     int		br_nest = 0;
5631     char_u	*p;
5632     int		len;
5633     int		vim9script = in_vim9script();
5634 
5635     if (expr_start != NULL)
5636     {
5637 	*expr_start = NULL;
5638 	*expr_end = NULL;
5639     }
5640 
5641     // Quick check for valid starting character.
5642     if ((flags & FNE_CHECK_START) && !eval_isnamec1(*arg)
5643 						&& (*arg != '{' || vim9script))
5644 	return arg;
5645 
5646     for (p = arg; *p != NUL
5647 		    && (eval_isnamec(*p)
5648 			|| (*p == '{' && !vim9script)
5649 			|| ((flags & FNE_INCL_BR) && (*p == '['
5650 					 || (*p == '.' && eval_isdictc(p[1]))))
5651 			|| mb_nest != 0
5652 			|| br_nest != 0); MB_PTR_ADV(p))
5653     {
5654 	if (*p == '\'')
5655 	{
5656 	    // skip over 'string' to avoid counting [ and ] inside it.
5657 	    for (p = p + 1; *p != NUL && *p != '\''; MB_PTR_ADV(p))
5658 		;
5659 	    if (*p == NUL)
5660 		break;
5661 	}
5662 	else if (*p == '"')
5663 	{
5664 	    // skip over "str\"ing" to avoid counting [ and ] inside it.
5665 	    for (p = p + 1; *p != NUL && *p != '"'; MB_PTR_ADV(p))
5666 		if (*p == '\\' && p[1] != NUL)
5667 		    ++p;
5668 	    if (*p == NUL)
5669 		break;
5670 	}
5671 	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
5672 	{
5673 	    // "s:" is start of "s:var", but "n:" is not and can be used in
5674 	    // slice "[n:]".  Also "xx:" is not a namespace. But {ns}: is.
5675 	    len = (int)(p - arg);
5676 	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
5677 		    || (len > 1 && p[-1] != '}'))
5678 		break;
5679 	}
5680 
5681 	if (mb_nest == 0)
5682 	{
5683 	    if (*p == '[')
5684 		++br_nest;
5685 	    else if (*p == ']')
5686 		--br_nest;
5687 	}
5688 
5689 	if (br_nest == 0 && !vim9script)
5690 	{
5691 	    if (*p == '{')
5692 	    {
5693 		mb_nest++;
5694 		if (expr_start != NULL && *expr_start == NULL)
5695 		    *expr_start = p;
5696 	    }
5697 	    else if (*p == '}')
5698 	    {
5699 		mb_nest--;
5700 		if (expr_start != NULL && mb_nest == 0 && *expr_end == NULL)
5701 		    *expr_end = p;
5702 	    }
5703 	}
5704     }
5705 
5706     return p;
5707 }
5708 
5709 /*
5710  * Expands out the 'magic' {}'s in a variable/function name.
5711  * Note that this can call itself recursively, to deal with
5712  * constructs like foo{bar}{baz}{bam}
5713  * The four pointer arguments point to "foo{expre}ss{ion}bar"
5714  *			"in_start"      ^
5715  *			"expr_start"	   ^
5716  *			"expr_end"		 ^
5717  *			"in_end"			    ^
5718  *
5719  * Returns a new allocated string, which the caller must free.
5720  * Returns NULL for failure.
5721  */
5722     static char_u *
5723 make_expanded_name(
5724     char_u	*in_start,
5725     char_u	*expr_start,
5726     char_u	*expr_end,
5727     char_u	*in_end)
5728 {
5729     char_u	c1;
5730     char_u	*retval = NULL;
5731     char_u	*temp_result;
5732 
5733     if (expr_end == NULL || in_end == NULL)
5734 	return NULL;
5735     *expr_start	= NUL;
5736     *expr_end = NUL;
5737     c1 = *in_end;
5738     *in_end = NUL;
5739 
5740     temp_result = eval_to_string(expr_start + 1, FALSE);
5741     if (temp_result != NULL)
5742     {
5743 	retval = alloc(STRLEN(temp_result) + (expr_start - in_start)
5744 						   + (in_end - expr_end) + 1);
5745 	if (retval != NULL)
5746 	{
5747 	    STRCPY(retval, in_start);
5748 	    STRCAT(retval, temp_result);
5749 	    STRCAT(retval, expr_end + 1);
5750 	}
5751     }
5752     vim_free(temp_result);
5753 
5754     *in_end = c1;		// put char back for error messages
5755     *expr_start = '{';
5756     *expr_end = '}';
5757 
5758     if (retval != NULL)
5759     {
5760 	temp_result = find_name_end(retval, &expr_start, &expr_end, 0);
5761 	if (expr_start != NULL)
5762 	{
5763 	    // Further expansion!
5764 	    temp_result = make_expanded_name(retval, expr_start,
5765 						       expr_end, temp_result);
5766 	    vim_free(retval);
5767 	    retval = temp_result;
5768 	}
5769     }
5770 
5771     return retval;
5772 }
5773 
5774 /*
5775  * Return TRUE if character "c" can be used in a variable or function name.
5776  * Does not include '{' or '}' for magic braces.
5777  */
5778     int
5779 eval_isnamec(int c)
5780 {
5781     return ASCII_ISALNUM(c) || c == '_' || c == ':' || c == AUTOLOAD_CHAR;
5782 }
5783 
5784 /*
5785  * Return TRUE if character "c" can be used as the first character in a
5786  * variable or function name (excluding '{' and '}').
5787  */
5788     int
5789 eval_isnamec1(int c)
5790 {
5791     return ASCII_ISALPHA(c) || c == '_';
5792 }
5793 
5794 /*
5795  * Return TRUE if character "c" can be used as the first character of a
5796  * dictionary key.
5797  */
5798     int
5799 eval_isdictc(int c)
5800 {
5801     return ASCII_ISALNUM(c) || c == '_';
5802 }
5803 
5804 /*
5805  * Handle:
5806  * - expr[expr], expr[expr:expr] subscript
5807  * - ".name" lookup
5808  * - function call with Funcref variable: func(expr)
5809  * - method call: var->method()
5810  *
5811  * Can all be combined in any order: dict.func(expr)[idx]['func'](expr)->len()
5812  */
5813     int
5814 handle_subscript(
5815     char_u	**arg,
5816     typval_T	*rettv,
5817     evalarg_T	*evalarg,
5818     int		verbose)	// give error messages
5819 {
5820     int		evaluate = evalarg != NULL
5821 				      && (evalarg->eval_flags & EVAL_EVALUATE);
5822     int		ret = OK;
5823     dict_T	*selfdict = NULL;
5824     int		check_white = TRUE;
5825     int		getnext;
5826     char_u	*p;
5827 
5828     while (ret == OK)
5829     {
5830 	// When at the end of the line and ".name" or "->{" or "->X" follows in
5831 	// the next line then consume the line break.
5832 	p = eval_next_non_blank(*arg, evalarg, &getnext);
5833 	if (getnext
5834 	    && ((rettv->v_type == VAR_DICT && *p == '.' && eval_isdictc(p[1]))
5835 		|| (p[0] == '-' && p[1] == '>' && (p[2] == '{'
5836 			|| ASCII_ISALPHA(in_vim9script() ? *skipwhite(p + 2)
5837 								    : p[2])))))
5838 	{
5839 	    *arg = eval_next_line(evalarg);
5840 	    p = *arg;
5841 	    check_white = FALSE;
5842 	}
5843 
5844 	if (rettv->v_type == VAR_ANY)
5845 	{
5846 	    char_u	*exp_name;
5847 	    int		cc;
5848 	    int		idx;
5849 	    ufunc_T	*ufunc;
5850 	    type_T	*type;
5851 
5852 	    // Found script from "import * as {name}", script item name must
5853 	    // follow.
5854 	    if (**arg != '.')
5855 	    {
5856 		if (verbose)
5857 		    semsg(_(e_expected_str_but_got_str), "'.'", *arg);
5858 		ret = FAIL;
5859 		break;
5860 	    }
5861 	    ++*arg;
5862 	    if (IS_WHITE_OR_NUL(**arg))
5863 	    {
5864 		if (verbose)
5865 		    emsg(_(e_no_white_space_allowed_after_dot));
5866 		ret = FAIL;
5867 		break;
5868 	    }
5869 
5870 	    // isolate the name
5871 	    exp_name = *arg;
5872 	    while (eval_isnamec(**arg))
5873 		++*arg;
5874 	    cc = **arg;
5875 	    **arg = NUL;
5876 
5877 	    idx = find_exported(rettv->vval.v_number, exp_name, &ufunc, &type,
5878 						  evalarg->eval_cctx, verbose);
5879 	    **arg = cc;
5880 	    *arg = skipwhite(*arg);
5881 
5882 	    if (idx < 0 && ufunc == NULL)
5883 	    {
5884 		ret = FAIL;
5885 		break;
5886 	    }
5887 	    if (idx >= 0)
5888 	    {
5889 		scriptitem_T    *si = SCRIPT_ITEM(rettv->vval.v_number);
5890 		svar_T		*sv = ((svar_T *)si->sn_var_vals.ga_data) + idx;
5891 
5892 		copy_tv(sv->sv_tv, rettv);
5893 	    }
5894 	    else
5895 	    {
5896 		rettv->v_type = VAR_FUNC;
5897 		rettv->vval.v_string = vim_strsave(ufunc->uf_name);
5898 	    }
5899 	}
5900 
5901 	if ((**arg == '(' && (!evaluate || rettv->v_type == VAR_FUNC
5902 			    || rettv->v_type == VAR_PARTIAL))
5903 		    && (!check_white || !VIM_ISWHITE(*(*arg - 1))))
5904 	{
5905 	    ret = call_func_rettv(arg, evalarg, rettv, evaluate,
5906 							       selfdict, NULL);
5907 
5908 	    // Stop the expression evaluation when immediately aborting on
5909 	    // error, or when an interrupt occurred or an exception was thrown
5910 	    // but not caught.
5911 	    if (aborting())
5912 	    {
5913 		if (ret == OK)
5914 		    clear_tv(rettv);
5915 		ret = FAIL;
5916 	    }
5917 	    dict_unref(selfdict);
5918 	    selfdict = NULL;
5919 	}
5920 	else if (p[0] == '-' && p[1] == '>')
5921 	{
5922 	    if (in_vim9script())
5923 		*arg = skipwhite(p + 2);
5924 	    else
5925 		*arg = p + 2;
5926 	    if (ret == OK)
5927 	    {
5928 		if (VIM_ISWHITE(**arg))
5929 		{
5930 		    emsg(_(e_nowhitespace));
5931 		    ret = FAIL;
5932 		}
5933 		else if ((**arg == '{' && !in_vim9script()) || **arg == '(')
5934 		    // expr->{lambda}() or expr->(lambda)()
5935 		    ret = eval_lambda(arg, rettv, evalarg, verbose);
5936 		else
5937 		    // expr->name()
5938 		    ret = eval_method(arg, rettv, evalarg, verbose);
5939 	    }
5940 	}
5941 	// "." is ".name" lookup when we found a dict or when evaluating and
5942 	// scriptversion is at least 2, where string concatenation is "..".
5943 	else if (**arg == '['
5944 		|| (**arg == '.' && (rettv->v_type == VAR_DICT
5945 			|| (!evaluate
5946 			    && (*arg)[1] != '.'
5947 			    && current_sctx.sc_version >= 2))))
5948 	{
5949 	    dict_unref(selfdict);
5950 	    if (rettv->v_type == VAR_DICT)
5951 	    {
5952 		selfdict = rettv->vval.v_dict;
5953 		if (selfdict != NULL)
5954 		    ++selfdict->dv_refcount;
5955 	    }
5956 	    else
5957 		selfdict = NULL;
5958 	    if (eval_index(arg, rettv, evalarg, verbose) == FAIL)
5959 	    {
5960 		clear_tv(rettv);
5961 		ret = FAIL;
5962 	    }
5963 	}
5964 	else
5965 	    break;
5966     }
5967 
5968     // Turn "dict.Func" into a partial for "Func" bound to "dict".
5969     // Don't do this when "Func" is already a partial that was bound
5970     // explicitly (pt_auto is FALSE).
5971     if (selfdict != NULL
5972 	    && (rettv->v_type == VAR_FUNC
5973 		|| (rettv->v_type == VAR_PARTIAL
5974 		    && (rettv->vval.v_partial->pt_auto
5975 			|| rettv->vval.v_partial->pt_dict == NULL))))
5976 	selfdict = make_partial(selfdict, rettv);
5977 
5978     dict_unref(selfdict);
5979     return ret;
5980 }
5981 
5982 /*
5983  * Make a copy of an item.
5984  * Lists and Dictionaries are also copied.  A deep copy if "deep" is set.
5985  * For deepcopy() "copyID" is zero for a full copy or the ID for when a
5986  * reference to an already copied list/dict can be used.
5987  * Returns FAIL or OK.
5988  */
5989     int
5990 item_copy(
5991     typval_T	*from,
5992     typval_T	*to,
5993     int		deep,
5994     int		copyID)
5995 {
5996     static int	recurse = 0;
5997     int		ret = OK;
5998 
5999     if (recurse >= DICT_MAXNEST)
6000     {
6001 	emsg(_("E698: variable nested too deep for making a copy"));
6002 	return FAIL;
6003     }
6004     ++recurse;
6005 
6006     switch (from->v_type)
6007     {
6008 	case VAR_NUMBER:
6009 	case VAR_FLOAT:
6010 	case VAR_STRING:
6011 	case VAR_FUNC:
6012 	case VAR_PARTIAL:
6013 	case VAR_BOOL:
6014 	case VAR_SPECIAL:
6015 	case VAR_JOB:
6016 	case VAR_CHANNEL:
6017 	case VAR_INSTR:
6018 	    copy_tv(from, to);
6019 	    break;
6020 	case VAR_LIST:
6021 	    to->v_type = VAR_LIST;
6022 	    to->v_lock = 0;
6023 	    if (from->vval.v_list == NULL)
6024 		to->vval.v_list = NULL;
6025 	    else if (copyID != 0 && from->vval.v_list->lv_copyID == copyID)
6026 	    {
6027 		// use the copy made earlier
6028 		to->vval.v_list = from->vval.v_list->lv_copylist;
6029 		++to->vval.v_list->lv_refcount;
6030 	    }
6031 	    else
6032 		to->vval.v_list = list_copy(from->vval.v_list, deep, copyID);
6033 	    if (to->vval.v_list == NULL)
6034 		ret = FAIL;
6035 	    break;
6036 	case VAR_BLOB:
6037 	    ret = blob_copy(from->vval.v_blob, to);
6038 	    break;
6039 	case VAR_DICT:
6040 	    to->v_type = VAR_DICT;
6041 	    to->v_lock = 0;
6042 	    if (from->vval.v_dict == NULL)
6043 		to->vval.v_dict = NULL;
6044 	    else if (copyID != 0 && from->vval.v_dict->dv_copyID == copyID)
6045 	    {
6046 		// use the copy made earlier
6047 		to->vval.v_dict = from->vval.v_dict->dv_copydict;
6048 		++to->vval.v_dict->dv_refcount;
6049 	    }
6050 	    else
6051 		to->vval.v_dict = dict_copy(from->vval.v_dict, deep, copyID);
6052 	    if (to->vval.v_dict == NULL)
6053 		ret = FAIL;
6054 	    break;
6055 	case VAR_UNKNOWN:
6056 	case VAR_ANY:
6057 	case VAR_VOID:
6058 	    internal_error_no_abort("item_copy(UNKNOWN)");
6059 	    ret = FAIL;
6060     }
6061     --recurse;
6062     return ret;
6063 }
6064 
6065     void
6066 echo_one(typval_T *rettv, int with_space, int *atstart, int *needclr)
6067 {
6068     char_u	*tofree;
6069     char_u	numbuf[NUMBUFLEN];
6070     char_u	*p = echo_string(rettv, &tofree, numbuf, get_copyID());
6071 
6072     if (*atstart)
6073     {
6074 	*atstart = FALSE;
6075 	// Call msg_start() after eval1(), evaluating the expression
6076 	// may cause a message to appear.
6077 	if (with_space)
6078 	{
6079 	    // Mark the saved text as finishing the line, so that what
6080 	    // follows is displayed on a new line when scrolling back
6081 	    // at the more prompt.
6082 	    msg_sb_eol();
6083 	    msg_start();
6084 	}
6085     }
6086     else if (with_space)
6087 	msg_puts_attr(" ", echo_attr);
6088 
6089     if (p != NULL)
6090 	for ( ; *p != NUL && !got_int; ++p)
6091 	{
6092 	    if (*p == '\n' || *p == '\r' || *p == TAB)
6093 	    {
6094 		if (*p != TAB && *needclr)
6095 		{
6096 		    // remove any text still there from the command
6097 		    msg_clr_eos();
6098 		    *needclr = FALSE;
6099 		}
6100 		msg_putchar_attr(*p, echo_attr);
6101 	    }
6102 	    else
6103 	    {
6104 		if (has_mbyte)
6105 		{
6106 		    int i = (*mb_ptr2len)(p);
6107 
6108 		    (void)msg_outtrans_len_attr(p, i, echo_attr);
6109 		    p += i - 1;
6110 		}
6111 		else
6112 		    (void)msg_outtrans_len_attr(p, 1, echo_attr);
6113 	    }
6114 	}
6115     vim_free(tofree);
6116 }
6117 
6118 /*
6119  * ":echo expr1 ..."	print each argument separated with a space, add a
6120  *			newline at the end.
6121  * ":echon expr1 ..."	print each argument plain.
6122  */
6123     void
6124 ex_echo(exarg_T *eap)
6125 {
6126     char_u	*arg = eap->arg;
6127     typval_T	rettv;
6128     char_u	*arg_start;
6129     int		needclr = TRUE;
6130     int		atstart = TRUE;
6131     int		did_emsg_before = did_emsg;
6132     int		called_emsg_before = called_emsg;
6133     evalarg_T	evalarg;
6134 
6135     fill_evalarg_from_eap(&evalarg, eap, eap->skip);
6136 
6137     if (eap->skip)
6138 	++emsg_skip;
6139     while ((!ends_excmd2(eap->cmd, arg) || *arg == '"') && !got_int)
6140     {
6141 	// If eval1() causes an error message the text from the command may
6142 	// still need to be cleared. E.g., "echo 22,44".
6143 	need_clr_eos = needclr;
6144 
6145 	arg_start = arg;
6146 	if (eval1(&arg, &rettv, &evalarg) == FAIL)
6147 	{
6148 	    /*
6149 	     * Report the invalid expression unless the expression evaluation
6150 	     * has been cancelled due to an aborting error, an interrupt, or an
6151 	     * exception.
6152 	     */
6153 	    if (!aborting() && did_emsg == did_emsg_before
6154 					  && called_emsg == called_emsg_before)
6155 		semsg(_(e_invalid_expression_str), arg_start);
6156 	    need_clr_eos = FALSE;
6157 	    break;
6158 	}
6159 	need_clr_eos = FALSE;
6160 
6161 	if (!eap->skip)
6162 	{
6163 	    if (rettv.v_type == VAR_VOID)
6164 	    {
6165 		semsg(_(e_expression_does_not_result_in_value_str), arg_start);
6166 		break;
6167 	    }
6168 	    echo_one(&rettv, eap->cmdidx == CMD_echo, &atstart, &needclr);
6169 	}
6170 
6171 	clear_tv(&rettv);
6172 	arg = skipwhite(arg);
6173     }
6174     eap->nextcmd = check_nextcmd(arg);
6175     clear_evalarg(&evalarg, eap);
6176 
6177     if (eap->skip)
6178 	--emsg_skip;
6179     else
6180     {
6181 	// remove text that may still be there from the command
6182 	if (needclr)
6183 	    msg_clr_eos();
6184 	if (eap->cmdidx == CMD_echo)
6185 	    msg_end();
6186     }
6187 }
6188 
6189 /*
6190  * ":echohl {name}".
6191  */
6192     void
6193 ex_echohl(exarg_T *eap)
6194 {
6195     echo_attr = syn_name2attr(eap->arg);
6196 }
6197 
6198 /*
6199  * Returns the :echo attribute
6200  */
6201     int
6202 get_echo_attr(void)
6203 {
6204     return echo_attr;
6205 }
6206 
6207 /*
6208  * ":execute expr1 ..."	execute the result of an expression.
6209  * ":echomsg expr1 ..."	Print a message
6210  * ":echoerr expr1 ..."	Print an error
6211  * ":echoconsole expr1 ..." Print a message on stdout
6212  * Each gets spaces around each argument and a newline at the end for
6213  * echo commands
6214  */
6215     void
6216 ex_execute(exarg_T *eap)
6217 {
6218     char_u	*arg = eap->arg;
6219     typval_T	rettv;
6220     int		ret = OK;
6221     char_u	*p;
6222     garray_T	ga;
6223     int		len;
6224     long	start_lnum = SOURCING_LNUM;
6225 
6226     ga_init2(&ga, 1, 80);
6227 
6228     if (eap->skip)
6229 	++emsg_skip;
6230     while (!ends_excmd2(eap->cmd, arg) || *arg == '"')
6231     {
6232 	ret = eval1_emsg(&arg, &rettv, eap);
6233 	if (ret == FAIL)
6234 	    break;
6235 
6236 	if (!eap->skip)
6237 	{
6238 	    char_u   buf[NUMBUFLEN];
6239 
6240 	    if (eap->cmdidx == CMD_execute)
6241 	    {
6242 		if (rettv.v_type == VAR_CHANNEL || rettv.v_type == VAR_JOB)
6243 		{
6244 		    semsg(_(e_using_invalid_value_as_string_str),
6245 						  vartype_name(rettv.v_type));
6246 		    p = NULL;
6247 		}
6248 		else
6249 		    p = tv_get_string_buf(&rettv, buf);
6250 	    }
6251 	    else
6252 		p = tv_stringify(&rettv, buf);
6253 	    if (p == NULL)
6254 	    {
6255 		clear_tv(&rettv);
6256 		ret = FAIL;
6257 		break;
6258 	    }
6259 	    len = (int)STRLEN(p);
6260 	    if (ga_grow(&ga, len + 2) == FAIL)
6261 	    {
6262 		clear_tv(&rettv);
6263 		ret = FAIL;
6264 		break;
6265 	    }
6266 	    if (ga.ga_len)
6267 		((char_u *)(ga.ga_data))[ga.ga_len++] = ' ';
6268 	    STRCPY((char_u *)(ga.ga_data) + ga.ga_len, p);
6269 	    ga.ga_len += len;
6270 	}
6271 
6272 	clear_tv(&rettv);
6273 	arg = skipwhite(arg);
6274     }
6275 
6276     if (ret != FAIL && ga.ga_data != NULL)
6277     {
6278 	// use the first line of continuation lines for messages
6279 	SOURCING_LNUM = start_lnum;
6280 
6281 	if (eap->cmdidx == CMD_echomsg || eap->cmdidx == CMD_echoerr)
6282 	{
6283 	    // Mark the already saved text as finishing the line, so that what
6284 	    // follows is displayed on a new line when scrolling back at the
6285 	    // more prompt.
6286 	    msg_sb_eol();
6287 	}
6288 
6289 	if (eap->cmdidx == CMD_echomsg)
6290 	{
6291 	    msg_attr(ga.ga_data, echo_attr);
6292 	    out_flush();
6293 	}
6294 	else if (eap->cmdidx == CMD_echoconsole)
6295 	{
6296 	    ui_write(ga.ga_data, (int)STRLEN(ga.ga_data), TRUE);
6297 	    ui_write((char_u *)"\r\n", 2, TRUE);
6298 	}
6299 	else if (eap->cmdidx == CMD_echoerr)
6300 	{
6301 	    int		save_did_emsg = did_emsg;
6302 
6303 	    // We don't want to abort following commands, restore did_emsg.
6304 	    emsg(ga.ga_data);
6305 	    if (!force_abort)
6306 		did_emsg = save_did_emsg;
6307 	}
6308 	else if (eap->cmdidx == CMD_execute)
6309 	    do_cmdline((char_u *)ga.ga_data,
6310 		       eap->getline, eap->cookie, DOCMD_NOWAIT|DOCMD_VERBOSE);
6311     }
6312 
6313     ga_clear(&ga);
6314 
6315     if (eap->skip)
6316 	--emsg_skip;
6317 
6318     eap->nextcmd = check_nextcmd(arg);
6319 }
6320 
6321 /*
6322  * Skip over the name of an option: "&option", "&g:option" or "&l:option".
6323  * "arg" points to the "&" or '+' when called, to "option" when returning.
6324  * Returns NULL when no option name found.  Otherwise pointer to the char
6325  * after the option name.
6326  */
6327     char_u *
6328 find_option_end(char_u **arg, int *opt_flags)
6329 {
6330     char_u	*p = *arg;
6331 
6332     ++p;
6333     if (*p == 'g' && p[1] == ':')
6334     {
6335 	*opt_flags = OPT_GLOBAL;
6336 	p += 2;
6337     }
6338     else if (*p == 'l' && p[1] == ':')
6339     {
6340 	*opt_flags = OPT_LOCAL;
6341 	p += 2;
6342     }
6343     else
6344 	*opt_flags = 0;
6345 
6346     if (!ASCII_ISALPHA(*p))
6347 	return NULL;
6348     *arg = p;
6349 
6350     if (p[0] == 't' && p[1] == '_' && p[2] != NUL && p[3] != NUL)
6351 	p += 4;	    // termcap option
6352     else
6353 	while (ASCII_ISALPHA(*p))
6354 	    ++p;
6355     return p;
6356 }
6357 
6358 /*
6359  * Display script name where an item was last set.
6360  * Should only be invoked when 'verbose' is non-zero.
6361  */
6362     void
6363 last_set_msg(sctx_T script_ctx)
6364 {
6365     char_u *p;
6366 
6367     if (script_ctx.sc_sid != 0)
6368     {
6369 	p = home_replace_save(NULL, get_scriptname(script_ctx.sc_sid));
6370 	if (p != NULL)
6371 	{
6372 	    verbose_enter();
6373 	    msg_puts(_("\n\tLast set from "));
6374 	    msg_puts((char *)p);
6375 	    if (script_ctx.sc_lnum > 0)
6376 	    {
6377 		msg_puts(_(line_msg));
6378 		msg_outnum((long)script_ctx.sc_lnum);
6379 	    }
6380 	    verbose_leave();
6381 	    vim_free(p);
6382 	}
6383     }
6384 }
6385 
6386 #endif // FEAT_EVAL
6387 
6388 /*
6389  * Perform a substitution on "str" with pattern "pat" and substitute "sub".
6390  * When "sub" is NULL "expr" is used, must be a VAR_FUNC or VAR_PARTIAL.
6391  * "flags" can be "g" to do a global substitute.
6392  * Returns an allocated string, NULL for error.
6393  */
6394     char_u *
6395 do_string_sub(
6396     char_u	*str,
6397     char_u	*pat,
6398     char_u	*sub,
6399     typval_T	*expr,
6400     char_u	*flags)
6401 {
6402     int		sublen;
6403     regmatch_T	regmatch;
6404     int		i;
6405     int		do_all;
6406     char_u	*tail;
6407     char_u	*end;
6408     garray_T	ga;
6409     char_u	*ret;
6410     char_u	*save_cpo;
6411     char_u	*zero_width = NULL;
6412 
6413     // Make 'cpoptions' empty, so that the 'l' flag doesn't work here
6414     save_cpo = p_cpo;
6415     p_cpo = empty_option;
6416 
6417     ga_init2(&ga, 1, 200);
6418 
6419     do_all = (flags[0] == 'g');
6420 
6421     regmatch.rm_ic = p_ic;
6422     regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
6423     if (regmatch.regprog != NULL)
6424     {
6425 	tail = str;
6426 	end = str + STRLEN(str);
6427 	while (vim_regexec_nl(&regmatch, str, (colnr_T)(tail - str)))
6428 	{
6429 	    // Skip empty match except for first match.
6430 	    if (regmatch.startp[0] == regmatch.endp[0])
6431 	    {
6432 		if (zero_width == regmatch.startp[0])
6433 		{
6434 		    // avoid getting stuck on a match with an empty string
6435 		    i = mb_ptr2len(tail);
6436 		    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail,
6437 								   (size_t)i);
6438 		    ga.ga_len += i;
6439 		    tail += i;
6440 		    continue;
6441 		}
6442 		zero_width = regmatch.startp[0];
6443 	    }
6444 
6445 	    /*
6446 	     * Get some space for a temporary buffer to do the substitution
6447 	     * into.  It will contain:
6448 	     * - The text up to where the match is.
6449 	     * - The substituted text.
6450 	     * - The text after the match.
6451 	     */
6452 	    sublen = vim_regsub(&regmatch, sub, expr, tail, FALSE, TRUE, FALSE);
6453 	    if (ga_grow(&ga, (int)((end - tail) + sublen -
6454 			    (regmatch.endp[0] - regmatch.startp[0]))) == FAIL)
6455 	    {
6456 		ga_clear(&ga);
6457 		break;
6458 	    }
6459 
6460 	    // copy the text up to where the match is
6461 	    i = (int)(regmatch.startp[0] - tail);
6462 	    mch_memmove((char_u *)ga.ga_data + ga.ga_len, tail, (size_t)i);
6463 	    // add the substituted text
6464 	    (void)vim_regsub(&regmatch, sub, expr, (char_u *)ga.ga_data
6465 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
6466 	    ga.ga_len += i + sublen - 1;
6467 	    tail = regmatch.endp[0];
6468 	    if (*tail == NUL)
6469 		break;
6470 	    if (!do_all)
6471 		break;
6472 	}
6473 
6474 	if (ga.ga_data != NULL)
6475 	    STRCPY((char *)ga.ga_data + ga.ga_len, tail);
6476 
6477 	vim_regfree(regmatch.regprog);
6478     }
6479 
6480     ret = vim_strsave(ga.ga_data == NULL ? str : (char_u *)ga.ga_data);
6481     ga_clear(&ga);
6482     if (p_cpo == empty_option)
6483 	p_cpo = save_cpo;
6484     else
6485     {
6486 	// Darn, evaluating {sub} expression or {expr} changed the value.
6487 	// If it's still empty it was changed and restored, need to restore in
6488 	// the complicated way.
6489 	if (*p_cpo == NUL)
6490 	    set_option_value((char_u *)"cpo", 0L, save_cpo, 0);
6491 	free_string_option(save_cpo);
6492     }
6493 
6494     return ret;
6495 }
6496